-7x^2+13x+9=-19+13xна идите корен

Question

-7x^2+13x+9=-19+13x
на идите корен

Answer 1

-7x^2 + 13x + 9 = - 19 + 13x
0 = 7x^2 - 13x - 9 - 19 + 13x
7x^2 - 28 = 0
7x^2 = 28
x^2 = 4
Sqrt(4) = 2  или - 2