急求三道八上数学题

题目

急求三道八上数学题<因式分解>

答案

3x²-4xy-2y²=5x²-2(x²+2xy+y²)=5x²-2(x+y)²=(√5x)²-[√2(x+y)]²=[√5x+√2(x+y)][√5x-√2(x+y)]=[(√5+√2)x+√2y][(√5-√2)x-√2y] 2a²-3ab-b²=2[a...