Solve for x in the equation x2+20x+100=36

Question

asked Apr 17, 2019 185k views

2 Answers

Parkerproject · Answer 1 · 2019-04-23T21:25:01+0000

Answer:

x = -4 and x = -16.

Explanation:

We have the equation,

x^(2)+20x+100=36

i.e.
x^(2)+20x+64=0

As the solution of a quadratic equation
ax^(2)+bx+c=0 is given by
$x=\frac{-b\pm \sqrt{b^(2)-4ac}}{2a}$ .

On comparing, a = 1, b = 20, c = 64.

So, the solution is,

$x=\frac{-20\pm \sqrt{(20)^(2)-4* 1* 64}}{2a* 1}$ .

i.e.
$x=(-20\pm √(400-256))/(2)$ .

i.e.
$x=(-20\pm √(144))/(2)$ .

i.e.
$x=(-20\pm 12)/(2)$ .

i.e.
x=(-20+12)/(2) and
x=(-20-12)/(2) .

i.e.
x=(-8)/(2) and
x=(-32)/(2) .

i.e. x = -4 and x = -16

Thus, the solution of the given equation is x = -4 and x = -16.