Deduce the Sum of the Exponents

Algebra Level 1

2 x = 1 2 y , x + y = ? \large 2^x=\dfrac{1}{2^y}, \quad\quad\quad x + y = \ ?

Depends on the number 1 0 1 -1

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.

12 solutions

Trevor Arashiro
Jan 1, 2015

1 = 2 0 1=2^0


2 x = 1 2 y ( 2 x ) ( 2 y ) = 1 2 x + y = 1 2 x + y = 2 0 x + y = 0 \begin{aligned} 2^x &=& \dfrac{1}{2^y}\\ (2^x)(2^y) &=& 1\\ 2^{x+y} &=& 1\\ 2^{x+y} &=& 2^0\\ \therefore x+y &=& 0\\ \end{aligned}

Could it be 2^x=2^-y So x=-y And x+y=0

aisha ajaj - 4 years, 8 months ago

That is what I did

Joshua Olayanju - 1 year ago
André Andrade
Jan 13, 2016

Youssef Hassan F
Jan 8, 2016

2^x=2^-y

so x is negative and y is positive

and -x = y

then x + y = 0

I did it that way too

Matheus Henrique - 5 years, 2 months ago

Anything to the negative power is going to be positive when it is made in its reciprocal form. Since here we have 2^x, keep "x" as -1. Then y=1. So we get x + y = -1 + 1 = 0

Mana Mana
Jun 21, 2016

I also used the logarithm... 2 x = 1 2 y 2 x = 1 2 y log 2 2 x = log 2 2 y x log 2 2 = y log 2 2 x 1 = y 1 x + y = 0 \begin{aligned} 2^{x} &= \frac{1}{2^{y}}\\ 2^{x} &= 1 \cdot 2^{-y}\\ \log_{2} 2^{x} &= \log_{2} 2^{-y}\\ x \cdot \log_{2} 2 &= -y \cdot \log_{2} 2\\ x \cdot 1 &= -y \cdot 1\\ x + y &= 0\\ \end{aligned}

2 x = 1 2 y = 2 y x = y x ( y ) = 0 x + y = 0 2^x=\frac{1}{2^y}=2^{-y} \implies x=-y \implies x-(-y)=0 \implies x+y=\boxed{\large{0}}

  • 2 x = 1 2 y 2^{x} = \frac{1}{2^{y}}
  • 2 x 2 y 2^{x} \cdot 2^{y} = 1
  • 2 x + y 2^{x + y} = 2 0 2^{0}
  • x + y = 0 x + y = 0
Peter Michael
May 30, 2017

Exponent laws key

Isolate for 1, and solve

Product of powers give zero.

From the equation, we know that 2^x = 2^-y. So, it means x = -y. Then, x+y = 0

Razzi Masroor
Jun 19, 2016

to have 2^x=1/2^y, you would have to have x be negative so when you inverse , it becomes positive. That means that x=-y, o the answer is 0

2^x=1/2^y=2^-y =)x= -y =)x+y=0

Jeffrey Gyamerah
Mar 24, 2016

2^(-1) = 1/2^(1) :. (-1) + 1 = 0

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...