数学题,!在线等, 要过程 十万火急,(1) 4(b-a)(a+b)-(2a-3b)(3a-2b) (2) (a-b+c)(a-b-c)
问题描述:
数学题,!在线等, 要过程 十万火急,
(1) 4(b-a)(a+b)-(2a-3b)(3a-2b) (2) (a-b+c)(a-b-c)
答
(1) =4(b^2-a^2)-6a^2+13ab-6b^2
=-10a^2+13ab-2b^2
(2) =(a-b)^2-c^2
=a^2-2ab+b^2-c^2
答
(1)原式=4(b²-a²)-(6a²-4ab-9ab+6b²)
= -2b²-10a²+13ab
(2)原式=[(a-b)+c][(a-b)-c]
=(a-b)²-c²
=a²-2ab+b²-c²
答
1 4(b-a)(a+b)-(2a-3b)(3a-2b)=4a²-4b²+4ab-6b²-6a²+9ab =13ab-10a²-2b²
2 (a-b+c)(a-b-c)=[(a-b)+c][(a-b)-c]=(a-b)²-c²=a²-2ab+b²-c²
答
(1)4(b²-a²)-(6a²-9ab-4ab+6b²)
=4b²-4a²-6a²+9ab+4ab-6b²
= -2b²-10a²+13ab
(2)[(a-b)- c] [(a-b)+c]
= a²-2ab+b²-c²