Question

3x+4)2−(x−10)2 .

Escolha uma opção:
a. 10x2−4x+116
b. 8x2−4x−84
c. 8x2+44x−84
d. 8x2−44x−84
e. 8x2+116

Answer 1

Given:

Expression is

`(3x+4)^2-(x-10)^2`

To find:

The simplified form of the given expression.

Solution:

We have,

`(3x+4)^2-(x-10)^2`

Using
`(a+b)^2=a^2+2ab+b^2` and
`(a-b)^2=a^2-2ab+b^2`, we get

`=(3x)^2+2(3x)(4)+(4)^2-[(x)^2-2(x)(10)+(10)^2]`

`=9x^2+24x+16-[x^2-20x+100]`

`=9x^2+24x+16-x^2+20x-100`

On combining like term, we get

`=(9x^2-x^2)+(24x+20x)+(16-100)`

`=8x^2+44x+(-84)`

`=8x^2+44x-84`

Therefore, the correct option is c.