Question

先化简，再求值：（x+2)(x-3)+3(x-1)(x+1)-(2x-1)(2x+3)，其中x=-1/5

拜托！

Answer 1

（x+2)(x-3)+3(x-1)(x+1)-(2x-1)(2x+3)
=x^2-x-5+3x^2-3-4x^2-4x+3
=-5x-5
=-5(-1/5)-5
=1-5
=-4

Answer 2

原式=(x²-x-6)+3(x²-1)-(4x²+4x-3)
=x²-x-6+3x²-3-4x²-4x+3
=-5x-6
=-5×(-1/5)-6
=-5我也是初中生，求采纳啊！！！