a²-2ab=3 b²-ab=4 求-2a²+ab+3b²
问题描述:
a²-2ab=3 b²-ab=4 求-2a²+ab+3b²
答
-2a²+ab+3b² = -2(a²-2ab)+3b²-3ab = -2x3 + 3x4 = 6
a²-2ab=3 b²-ab=4 求-2a²+ab+3b²
-2a²+ab+3b² = -2(a²-2ab)+3b²-3ab = -2x3 + 3x4 = 6