分解因式(1)-4a³b²+6a²b³-6ab²(1)-4a³b²+6a²b³-6ab²(2)4x²y²-x²(3)(x-2y)²+6(2y-x)+9(4)121(a+b)²-25(a-b)²
问题描述:
分解因式(1)-4a³b²+6a²b³-6ab²
(1)-4a³b²+6a²b³-6ab²
(2)4x²y²-x²
(3)(x-2y)²+6(2y-x)+9
(4)121(a+b)²-25(a-b)²
答
(1)-4a³b²+6a²b³-6ab²
=-2ab²(2a²-3ab+3)
(2)4x²y²-x²
=x²(4y²-1)
=x²(2y+1)(2y-1)
以上两题考察的是提取公因式,把大家都有的写到扣号外面就好
(3)(x-2y)²+6(2y-x)+9
=(x-2y)²-6(x-2y)+9
=(x-2y-3)²
(4)121(a+b)²-25(a-b)²
=11²(a+b)²-5²(a-b)²
=[11(a+b)]²-[5(a-b)]²
=[11(a+b)+5(a-b)][11(a+b)-5(a-b)]
=(16a+6b)(6a+16b)
=4(8a+3b)(3a+8b)
答
(1)-4a³b²+6a²b³-6ab²
=-2ab²(2a²-3ab+3)
(2)4x²y²-x²
=x²(4y²-1)
=x²(2y+1)(2y-1)
(3)(x-2y)²+6(2y-x)+9
=(x-2y)²-6(x-2y)+9
=(x-2y-3)²
(4)121(a+b)²-25(a-b)²
=[11(a+b)+5(a-b)][11(a+b)-5(a-b)]
=(16a+6b)(6a+16b)
=4(8a+3b)(3a+8b)