Question

已知x的2次方减5x=14，求（x-1）乘以（2x-1）减去(x+1）的2次方+1的值

Answer 1

x^2 - 5x = 14x^2 - 5x -14 = 0(x-7)(x+2) = 0x = 7 或 -2你后面要求的算式 我看不太明白 不过我想 现在有了x的值 你应该可以自己算了吧

Answer 2

=2x^2-3x+1-x^2-2x-1+1
=x^2-5x+1
=14+1
=15

Answer 3

X^2-5X-14=0
x^2-5x=14
(x-1)(2x-1)-(x+1)^2+10
=2x^2-3x+1-(x^2+2x+1)+10
=x^2-5x+10
=14+10
=24