Question

已知2X的平方减2X减3等于0,求代数式X的平方减一分之小括号X减1括住的平方加X加1分之2X的平方减X的值

Answer 1

2x²-2x-3=0
则,2x²=2x+3

(x-1)²/(x²-1) + (2x²-x)/(x+1)
=(x-1)/(x+1) + (2x²-x)/(x+1)
=(2x²-1)/(x+1) 这步2x²=2x+3代入.
=(2x+3-1)/(x+1)
=2(x+1)/(x+1)
=2