Question

Complete the expression so that it forms a perfect square binomial- 3x^2+18x

Answer 1

-3x²+18x-27

Explanation:

Given :

-3X²+18x

perfect square : (a+b)²=a² + 2ab + b²

`(-3x^(2) )/(-3) +(18x)/(-3) ... something else` divide by -3 to have just a² type

x² -6x ...and something

compare with the perfect squere formula and we know a² is x² , a is x, so second term is 2xb and is -6x so b= -3

x²-6x+9 = (x-3)²

if you reverse and multiply by (-3) we have

-3x²+18x-27