Question

3x(squared)+6x-15=0 solve by completing the square??

Answer 1

3x^2 + 6x-15=0 devide away the 3
x^2 +2x -5 = 0 move five over
x^2+2x = 5 take half the b term and square it and add to both sides and use that number do make the binomial
(x+1)^2 = 6
x+1 = +- sqrt(6)
x = sqrt(6) -1 or -sqrt(6) - 1

Answer 2

when I say use that number for the binomial i mean 1/2 the b term not 1/2 the b term squared. so if it was like x^2 + 4x = 7 you would do (x+2)^2= 11. the first 2 is half the b term and the 11 is 7 + half the b term squared.