神马作文网八年级下册数学运用公式法测试题
来源：学生作业帮 编辑：神马作文网作业帮 分类：数学作业 时间：2024/11/10 19:41:37
八年级下册数学运用公式法测试题
49(a-b)" -16(a+b)"
=[7(a-b)+4(a+b)][7(a-b)-4(a+b)]
=(11a-3b)(3a-11b)
(2x+y)" - (x+2y)"
=(2x+y-x-2y)(2x+y+x+2y)
=(x-y)(3x+3y)
=3(x-y)(x+y)
(x"+y")" -x"y"
=(x"+y"+xy)(x"+y"-xy)
3ax"-3ay""
=3a(x"-y"")
=3a(x-y")(x+y")
P""-1
=(P"-1)(P"+1)
=(P-1)(P+1)(P"+1)
=[7(a-b)+4(a+b)][7(a-b)-4(a+b)]
=(11a-3b)(3a-11b)
(2x+y)" - (x+2y)"
=(2x+y-x-2y)(2x+y+x+2y)
=(x-y)(3x+3y)
=3(x-y)(x+y)
(x"+y")" -x"y"
=(x"+y"+xy)(x"+y"-xy)
3ax"-3ay""
=3a(x"-y"")
=3a(x-y")(x+y")
P""-1
=(P"-1)(P"+1)
=(P-1)(P+1)(P"+1)