Question

Solve the equation for all values of x by completing the square.
3x^2-60x+255=0

Answer 1

x=5 and x=15

Explanation:

3x^2-60x+225=0

3x^2-60x+225/3=0/3

x^2-20x+75=0

x^2-5x-15x+75=0

x(x-5)-15(x-5)=0

(x-5)(x-15)=0

x-5=0 x-15=0

x=5 x=15