填空题:9(x+2y)^2-25(x-2y)^2=[ ]^2-[ ]^29(x+2y)^2-25(x-2y)^2=[ ]^2-[ ]^2

来源:学生作业帮助网 编辑:六六作业网 时间:2024/11/25 21:19:01
填空题:9(x+2y)^2-25(x-2y)^2=[]^2-[]^29(x+2y)^2-25(x-2y)^2=[]^2-[]^2填空题:9(x+2y)^2-25(x-2y)^2=[]^2-[]^29(

填空题:9(x+2y)^2-25(x-2y)^2=[ ]^2-[ ]^29(x+2y)^2-25(x-2y)^2=[ ]^2-[ ]^2
填空题:9(x+2y)^2-25(x-2y)^2=[ ]^2-[ ]^2
9(x+2y)^2-25(x-2y)^2=[ ]^2-[ ]^2

填空题:9(x+2y)^2-25(x-2y)^2=[ ]^2-[ ]^29(x+2y)^2-25(x-2y)^2=[ ]^2-[ ]^2
9(x+2y)^2-25(x-2y)^2=[ ]^2-[ ]^2
=3^2(x+2y)^2-5^2(x-2y)^2
=[3(x+2y)]^2-[5(x-2y)]^2 公式是(a^n)×(b^n)=(ab)^n
=(3x+6y)^2-(5x-10y)^2
∴9(x+2y)^2-25(x-2y)^2=[3x+6y]^2-[5x-10y]^2

9(x+2y)^2-25(x-2y)^2=[3(x+2y) ]^2-[ 5(x-2y)]^2