Question

七年级下 求两道数学题答案

①(x+3y)^2(x-3y)^2
②(0.5m+n)(0.5m-n)(0.25m^2-n^2)
小数为分数（分数不好打） 求过程和结果

Answer 1

①(x+3y)^2(x-3y)^2
=（(x+3y)(x-3y)）^2
=(x^2-9y^2)^2
=x^4+81y^4-18x^2y^2
②(0.5m+n)(0.5m-n)(0.25m^2-n^2)
=(0.25m^2-n^2)(0.25m^2-n^2)
=0.625m^4-0.5m^2n^2+n^4

Answer 2

1、原式=[(x+3y)(x-3y)]^2=(x^2-9y^2)^2=x^4-18x^2y^2+81y^4
2、原式=(0.25m^2-n^2)(0.25m^2-n^2)=m^4/16-0.5m^2n^2+n^4

Answer 3

(x+3y)^2(x-3y)^2=(x^2-9y^2)^2
(0.5m+n)(0.5m-n)(0.25m^2-n^2) =(0.25m^2-n^2))(0.25m^2-n^2)=(0.25m^2-n^2)^2

Answer 4

①(x+3y)^2(x-3y)^2=(x+3y)(x-3y)(x+3y)(x-3y)=(x^2-9y^2)^2=x^4-18x^2y^2+81y^4
②(0.5m+n)(0.5m-n)(0.25m^2-n^2)=(0.5m+n)(0.5m-n)(0.5m+n)(0.5m-n)=(0.25m^2-n^2)(0.25m^2-n^2)=0.0625m^4-0.5m^2n^2+n^4

Answer 5

你让人空想呀

Answer 6

。。。。题呢