Question

Solve: x2 + 3x = 28
{-7, 4}
{-4, 7}
{-7, -4}
{7, 4}

Answer 1

change into x^2 + 3x - 28 = 0

factor out

Answer 2

x^2 + 3x = 28
x^2 + 3x -28 =0
(x+7)(x-4) =0
(x+7)=0 or (x-4) =0
Can you solve it?

Answer 3

Can you explain in brief for the 2nd and 3rd step

Answer 4

x^2 + 3x -28 =0
x^2 + 7x - 4x - 28 =0
x(x+7) - 4(x+7) =0
(x-4)(x+7) =0

Do I make it clearer to you?

Answer 5

k thanks
i made a mistake
sorry :/

Answer 6

Welcome and no worry!