Question

Solve –3x2 + 30x – 90 = 0

Answer 1

–3x2 + 30x – 90 = 0
-3(x^2-10x+9)=0
or x^2-10x+9=0
x^2-9x-x+9=0
x(x-9)-1(x-9)=0
(x-9)(x-1)=0
or x-9=0 or x-1=0
hence x=9 or x=1