Question

If x= 2 find the value of 80 - 4x^2

Answer 1

It's 16

Explanation:

Rearrange the equation by subtracting what is to the right of the equal sign from both sides of the equation :

x^2+(x-4)^2-(80^2)=0

Step by step solution :

STEP

1

:

1.1 80 = 24•5

(80)2 = (24•5)2 = 28 • 52

Equation at the end of step

1

:

((x2) + ((x - 4)2)) - (28•52) = 0

STEP

2

:

STEP

3

:

Pulling out like terms

3.1 Pull out like factors :

2x2 - 8x - 6384 = 2 • (x2 - 4x - 3192)

Trying to factor by splitting the middle term

3.2 Factoring x2 - 4x - 3192