Question

X³ - 45x= 4x²

Solve the following equation by factoring.

Answer 1

(x-9)(x+5)=0

Explanation:

x³ - 45x= 4x²

x^3-45x-4x^2=0

x(x^2-45-4x)=0

x(x^2-4x-45)=0. ( Arranging the equation in proper place to factorize)

x(x^2-(9-5)x-45)=0. (therefore, the product of 45 should be equal to 4 by sum or difference between those numbers)

x(x^2-9x+5x-45)=0

x{x(x-9)+5(x-9)}=0

x(x-9)(x+5)=0

Or,

(x-9)(x+5)=0

because;

x(x-9)(x+5)=0

(x-9)(x+5)=0/x

(x-9)(x+5)=0