Question

What are the solution(s) to the quadratic equation 40 - x2 = 0?

x= +2/10
x= +4/10
0
O
x = +2/5
0
x = +4/5

Answer 1

±2 sqrt(10) = x

Explanation:

40 - x^2 =0

Add x^2 to each side

40 -x^2 + x^2 = 0+x^2

40 = x^2

Take the square root of each side

±sqrt(40) = sqrt(x^2)

±sqrt(40) = x

±sqrt(4*10) = x

We know the sqrt(ab) = sqrt(a) sqrt(b)

±sqrt(4) sqrt(10) = x

±2 sqrt(10) = x