Question

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

x = +210
x = +4/10
x = +2,5
x = 14,5

Answer 1

±2sqrt(10) = x

Explanation:

40 - x^2 = 0

Add x^2 to each side

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

40 = x^2

Take the square root of each side

sqrt(40) = sqrt(x^2)

±sqrt(40) = x

±sqrt(4) sqrt(10) = x

±2sqrt(10) = x