So Close Already!

Logic Level 1

9 9 9 = 9 9 8 \Huge 9 \ \ 9 \ \ 9 \ \ = \ \ 9 \ \ 9 \ \ 8

Do there exist operations that can be performed to make this equation true?

Any operations can be used on both sides of this equation, so get creative!

Inspired by many Brilliant users' solutions:

If you're looking for a more specific challenge, is it possible to...

(1) Use only the 4 basic, arithmetic operators ( + , − , × , ÷ ) (+, -, \times, \div) and no parentheses?

(2) Use the permutations operator ( n P r ) (n \textbf{P} r) and/or the factorial operator to make this equation true?

(3) Make both sides = 10 , 1 , 0 , or − 1 = 10, 1, 0, \text{or } -1

No Yes

View wiki
Zandra Vinegar by Zandra Vinegar

This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try refreshing the page, (b) enabling javascript if it is disabled on your browser and, finally, (c) loading the non-javascript version of this page . We're sorry about the hassle.

54 solutions

Kay Xspre
Feb 15, 2016

( 9 − 9 ) / 9 = ( 9 − 9 ) / 8 (9-9)/9 = (9-9)/8

Yeah, I know this is kinda cheating :S...

20 Helpful 0 Interesting 0 Brilliant 0 Confused

(9/9)*9= (9/9)+8

Kartikey Gupta - 5 years, 4 months ago

Log in to reply

That is the best solution

Iyad Barghouti - 5 years, 3 months ago

9-(9/9)=(9/9)*8 ou seja 8=8

Ronaldo Zelizi Junior - 5 years, 3 months ago

Log in to reply

9+9+9=9+((9*(cube root 8))

Sparsho De - 5 years, 3 months ago

Yeah.. did the same.

raghav yadav - 5 years, 3 months ago

Mine is (9-9) 9=(9-9) 8 LOL

Desmond Yeung - 5 years, 4 months ago

Log in to reply

Mine is this

(9-9)!+9= 9+(9-8)!

Kevin Silva - 5 years, 4 months ago

Mine was the same as yours lmao

Chris Chris - 5 years, 4 months ago

lol, I think it's awesome!

Zandra Vinegar Staff - 5 years, 4 months ago

Hahahaha! I thought about exactly this.

Paulo Filho - 5 years, 3 months ago

999 > 998 that was mine

Jessica Lynch - 5 years, 3 months ago

This is no cheating this is genius.

João Arruda - 5 years, 3 months ago
Zandra Vinegar Staff
Feb 15, 2016

Here's a simple way to do it, but I'm curious to see what kinds of crazy ones people can come up with:

9 − ( 9 / 9 ) = ( 9 / 9 ) × 8 9 - (9 / 9) = (9 / 9) \times 8

(And, just to be clear, you don't need the parentheses. 9 − 9 / 9 = 9 / 9 × 8 9 - 9 / 9 = 9 / 9 \times 8 evaluates in the same order as the line above.)

13 Helpful 0 Interesting 1 Brilliant 0 Confused

I did 9 + 9 + 9 = 9+ 9*cuberoot(8)

Harsha Invader - 5 years, 3 months ago
Jamie Forsythe
Feb 16, 2016

9 + 9 + 9 = ( 9 / 9 ) + 8 \sqrt{9} + \sqrt{9} + \sqrt{9} = (9 / 9) + 8

8 Helpful 0 Interesting 0 Brilliant 0 Confused

Brilliant.

Mehul Arora - 5 years, 3 months ago
Jack Rawlin
Feb 16, 2016

9 9 9 = 9 9 8 \large 9~9~9 = 9~9~8

9 P 9 ⋅ 9 = 9 ⋅ 9 ⋅ 8 ! \large 9P9 \cdot 9 = 9 \cdot 9 \cdot 8!

Note: 9 P 9 = 9 ! ( 9 − 9 ) ! 9P9 = \frac{9!}{(9 - 9)!}

Does this count?

4 Helpful 0 Interesting 0 Brilliant 0 Confused

The facebook link said any operations are permissible... So yeah, it's valid I suppose.

Jack Lam - 5 years, 4 months ago
Chirag Tamhane
Feb 21, 2016

9 / 9 + 9 = 9 + 9 - 8

1 + 9 = 18 - 8 (BODMAS rule)

10 = 10

3 Helpful 0 Interesting 0 Brilliant 0 Confused

I'll go with this ☺

Jin Delavega - 5 years, 3 months ago
Natanael Flores
Feb 20, 2016

(9mod9)+9=9*(9mod8)

2 Helpful 0 Interesting 0 Brilliant 0 Confused

That's programming. Does that still count?

Monrelle Franshan - 5 years, 3 months ago

Log in to reply

I dont know lol, I hope it does

Natanael Flores - 5 years, 3 months ago
Harsh Shrivastava
Feb 15, 2016

1 Helpful 0 Interesting 0 Brilliant 0 Confused

Well, this is one solution :P

Mehul Arora - 5 years, 3 months ago
B D
Oct 3, 2018

Here is how I soled it 9 ! ∗ 9 ! : 9 ! = ( 9 + 9 ) : 8 9! * 9! : 9! = (9 + 9) : 8

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Noel Lo
Jun 3, 2016

OR: 9+9/9 = 9+9-8.

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Stephan Joldzic
Feb 23, 2016

(9-9)+9 = (9/9)+8

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Jatin Kulkarni
Feb 23, 2016

(9-9)+9=(9/9)+8

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Ben Mills
Feb 22, 2016

Once I got thinking, I realized there are many simple ways to do this. First one I thought of: (9 / 9) * 9 = 9 * (9 - 8).

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Jonathan Wilkie
Feb 22, 2016

I love numbers!

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Michael Hammill
Feb 21, 2016

9 + 9 + 9^0 = 9 + 9 + 8^0

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Charles Fortier
Feb 21, 2016

9 9/9=9 (9-8)

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Anweshan Bor
Feb 21, 2016

Multiply both sides by 0.

0 Helpful 0 Interesting 0 Brilliant 0 Confused

You can't, that would break the rules. You can only use the numbers already given. You added a zero.

Matthew Sult - 5 years, 3 months ago
Mikaela Lahn
Feb 21, 2016

9 + 9 - 9 = 9 / 9 + 8

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Harrison Bell
Feb 21, 2016

999x0=998x0

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Marvin Yu
Feb 21, 2016

9+9-9=9*(9-8)

9+9/9=9+9-8

9*9/9=9/9+8

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Philip Zook
Feb 21, 2016

9 - 9/9 = 9 - 9 + 8

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Daniel Schnoll
Feb 21, 2016

9 + (9-9) = 9 * (9-8) –> 9 + 0 = 9*1 –> 9=9

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Peter Crest
Feb 21, 2016

9+9-9=9/9+8

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Natalie Pak
Feb 21, 2016

9/9x9 = 9/9+8

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Carol Fisher
Feb 21, 2016

9 - 9 + 9 = 8 + 9 / 9

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Sam Pandya
Feb 21, 2016

with parenthesis : 9 + (9-9) = 9 / (9-8) Without parenthesis : 9 + 9 / 9 = 9 + 9 - 8

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Michael Brill
Feb 21, 2016

9^9/9 = sqr(9*9) ^ 8

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Suhaib Kalam
Feb 21, 2016

(9-9)×9=0 (9-9)×8=0

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Muhammad Jamal
Feb 21, 2016

9-9+9 = 9÷9+8

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Harrison Johns
Feb 21, 2016

9-9+9=9 9×(9-8)=9 Ta-da...

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Thomas Minahan
Feb 21, 2016

(9/9)^9=(9/9)^8

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Diwahar Kc
Feb 21, 2016

9*9/9=9/9+8

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Gabe Swallow
Feb 21, 2016

999 =/= 998

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Matthew Speight
Feb 21, 2016

(9-9)+9 = (9/9)+8

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Anmol Kumar
Feb 21, 2016

( 9 / 9 ) + 9 = ( 9 + 9 ) - 8 => 1 + 9 = 18 - 8 => 10 = 10 Hence, True.

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Oli Callaghan
Feb 21, 2016

9*(9/9) = 9^(9-8)

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Kostis Smanis
Feb 18, 2016

9^(9/9)=9^(9-8)

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Imran Ansari
Feb 18, 2016

9 9 9 = 9 9 8

9 + 9 - 9 = 9 * (9 - 8)

9 = 9

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Pranjit Handique
Feb 16, 2016

9^(9/9)=9^(9-8)

0 Helpful 0 Interesting 0 Brilliant 0 Confused

9 9 − 9 = 9 / ( 9 ! / 8 ! ) { 9 }^{ 9-9 }=9/(9!/8!)

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Alex Tirziu
Feb 16, 2016

9*9/9 = (9/9)+8

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Ian Carlo
Feb 16, 2016

9/9+9 = 9+9-8

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Samuel Morse
Feb 16, 2016

9x9/9=9x(9-8)=9

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Marco Vitale
Feb 16, 2016

9x9-9=(9^0)x9x8

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Anish Harsha
Feb 16, 2016

Just some changes,

9 × ( 9 / 9 ) = 9 × ( 9 − 8 ) 9 \times (9 / 9) = 9 \times (9 - 8)

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Liviu Țapu
Feb 16, 2016

9*9/9 = 9/9 + 8

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Amed Lolo
Feb 16, 2016

1St solution. 9+9-9=9\9+8. Or (9-9)×9=ln(9\9)×8

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Tanishq Bhatia
Feb 16, 2016

9-(9-9)!=9-(9-8)!

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Muhammed Li
Feb 16, 2016

9 - 9 + 9 = (9/9) + 8

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Triston Childs
Feb 16, 2016

9x (9/9)=(9/9)+8

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Anson Chui
Feb 16, 2016

( 9 − 9 ) × 9 = ( 9 − 9 ) × 8 ( 9 - 9 ) \times 9 = ( 9 - 9 ) \times 8

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Vivek Raveendran
Feb 16, 2016

9-[9/9]=9-[9/8]
where []= Greatest integer function

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Arindam Porel
Feb 16, 2016

9!×(9-9)!=9!×(9-8)!

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Andrew Lin
Feb 16, 2016

(9/9) 9=9 (9-8)

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Saatvik Jain
Feb 16, 2016

9+ (9/9) = 9+9-8

0 Helpful 0 Interesting 0 Brilliant 0 Confused

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...