5x^2+25x-111=-x^2-8x+9 срочно прошу вас

Question

5x^2+25x-111=-x^2-8x+9 срочно прошу вас

Answer 1

5x^2+25x-111=-x^2-8x+9
5x^2+25x-111+x^2+8x-9=0
6x^2+33x-120=0
2x^2+11x-40=0
D=121+4*2*40=441=21^2

x1=-11-21/4=-8
x2=-11+21/4=5/2