(1)若3a²-a-2=0,则5+2a-6a²等于多少[要因为所以的过程.]

问题描述:

(1)若3a²-a-2=0,则5+2a-6a²等于多少[要因为所以的过程.]
(2)已知x²-5x=14,求(x-1)(2x-1)-(x+1)²+1的值[要求同上]

1\3a²-a-2=0,(a-1)(3a+2)=0
a1=1,5+2a-6a²=5+2-6=1
a2=-2/3
5+2(-2/3)-6(-2/3)²=1
2\、(x-7)(x+2)=0
x=7或者x=-2
值等于15