It's just decimals

Number Theory Level 1

What is the value of 5. 6 2 − 3. 6 2 + 1.6 5.6^{2} - 3.6^{2} + 1.6 ?


The answer is 20.

Margaret Zheng by Margaret Zheng , 20, USA

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.

3 solutions

Margaret Zheng
May 10, 2016

Notice that 5. 6 2 − 3. 6 2 5.6^{2} - 3.6^{2} could be written as ( 5.6 − 3.6 ) ( 5.6 + 3.6 ) (5.6-3.6)(5.6+3.6) which gives us 2 × 9.2 = 18.4 2 \times 9.2 = 18.4 . Adding 1.6 to 18.4, we get 20 \boxed {20} .

3 Helpful 0 Interesting 0 Brilliant 0 Confused
Edwin Gray
Feb 25, 2019

5.6^2 - 3.6^2 = (5.6 - 3.6)(5.6 + 3.6) = (2)(9.2) = 18.4 + 1.6 = 20.

0 Helpful 0 Interesting 0 Brilliant 0 Confused
Ashish Menon
May 23, 2016

5.6 2 − 3.6 2 + 1.6 = ( 5.6 + 3.6 ) ( 5.6 − 3.6 ) + 1.6 = 9.2 × 2 + 1.6 = 18.4 + 1.6 = 20 {5.6}^2 - {3.6}^2 + 1.6 = (5.6 + 3.6)(5.6 - 3.6) + 1.6 = 9.2 × 2 + 1.6 = 18.4 + 1.6 = \color{#69047E}{\boxed{20}} .

0 Helpful 0 Interesting 0 Brilliant 0 Confused

0 pending reports

×

Problem Loading...

Note Loading...

Set Loading...