am+bm-cm
64-16a+a²
2(x-y)+a(x-y)
0.49x²-0.04y²
-4a²b+4ab-1
-3a³x+12ax³
m³n-2m²n²+mn³
分解因式:
(m-n)³+2n(n-m)²
1/2a³b+2a²b²+2ab³
已知a+b=-2,ab=-2/5.求a(a+b)(a-b)-a(a+b)²的值.
am+bm-cm
-4a²b²+4ab-1
已知a+b=-2,ab=-2/5.求a(a+b)(a-b)-a(a+b)²的值.这道题目我觉得是等于10.
能好好算算吗
am+bm-cm=m(a+b-c)
-4a²b²+4ab-1=-(4a²b²-4ab+1)=-(2ab-1)²
a(a+b)(a-b)-a(a+b)²
=a³-ab²-(a³+2a²b+ab²)
=-ab²-2a²b-ab²
=-ab(b+2a+b)
=-2ab(a+b)
=-2(-2/5)(-2)
=-8/5
=-1又3/5