Question

跪求各位帮我解决一道初一数学计算题，谢谢

化简（x-2) (x-3) + 2(x+6) (x-5)-3(n²-7x+13),并求当x=-2时的值

谢谢

Answer 1

（x-2) (x-3) + 2(x+6) (x-5)-3(x²-7x+13)
=（x-2) (x-3) + 2(x+6) (x-5)-3(x²-7x+10)-9
=（x-2) (x-3) + 2(x+6) (x-5)-3(x-2)(x-5)-9
=（x-2) (x-3-x+5) + 2(x+6-x+2) (x-5)-9
=(x-2) 2 + 2*8(x-5)-9
=18x-4-80-9
=18x-93
当x=-2时的值
原式=-36-93=-129

Answer 2

解：（x－2)(x－3)＋2(x＋6)(x-5)－3(x²-7x+13)
=x²-5x+6+2(x²+x-30)-3x²+21x-39
=3x²-3x-54-3x²+21x-39
=18x-93
当x=-2时，
原式=-36-93=-129

Answer 3

谢谢 这我是真不懂才来问的 4ab(-2a)-(-b ）×（1/2 a b)+10a （-3/5 b)+(-3.5a)×1/7 b =-8a b+1/2ab -6a b-1/2ab

Answer 4

I DONOT KNOW

Answer 5

不知道