Разложить на множители квадратный трёхчлен:
1)-6х²+7х-2

2)-4х²-7х+2

1) - 6x^2 - 7x - 2 = -(6x^2 + 7x +2) = - 6(x + 1/2)·(x+ 2/3)= = - 2·(x+1/2)·3(x+2/3) = -(2x+1)·(3x+2).D = 49 - 48 = 1; x= -1/2;x = - 2/3.2) - 4x^2 - 7x + 2 = - (4x^2 + 7x - 2) = - 4(x +2)(x- 1/4) == -(x+2)·4(x - 1/4) = - (x+2)(4x - 1) = (x+2)(1 - 4x).D = 49 + 32 = 81= 9^2;x = 1/4; x= - 2.