9x^2-1-(x^2+2x-x-2)=8
8x^2+1-x-8=0
8x^2-x-7=0
D=(-1)^2+4×7×8=225
x=1
x=-15/16
Объяснение:
9x^2 - 1 - x^2 + 2 +x -2x =8
8x^2 +1 -x=8
8x^2 - x= 7
8x^2 - x - 7 =0
D= 1 + 4×8×7=225=15^2
x1= 1 - 15 / 16 = - 14/16 = -7/8
x2= 1 +15/16 = 1
1 и -7/8
