contestada

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

Respuesta :

Given:

Expression is

[tex](3x+4)^2-(x-10)^2[/tex]

To find:

The simplified form of the given expression.

Solution:

We have,

[tex](3x+4)^2-(x-10)^2[/tex]

Using [tex](a+b)^2=a^2+2ab+b^2[/tex] and [tex](a-b)^2=a^2-2ab+b^2[/tex], we get

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

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

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

On combining like term, we get

[tex]=(9x^2-x^2)+(24x+20x)+(16-100)[/tex]

[tex]=8x^2+44x+(-84)[/tex]

[tex]=8x^2+44x-84[/tex]

Therefore, the correct option is c.