几道数学题目（初一）急!【做的好.快,加分!~】

【1】,填空
2/3=(4）/6=6/(9)=100/(150)
2x/3y=(4x²)/6xy=6xy/(9y²)=100x^2y^2/(150xy³)
【2】约分
-18xy/27x^2y^2=-2/(3xy)
-24n^2m^3/16n^3m^2=-3m/(2n)
12(x+y)^2/20(x+y)(x+2y)=3(x+y)/[5(x+2y)]
【4】判断是否是最简分式,不是的请化简
18/45xy,不是,=2/5xy
x+16/2x+16,是
25xy/15xz,不是,=5y/3z

【1】,填空
2/3=( 4）/6=6/(9 )=100/( 150)
2x/3y=( 4x^2)/6xy=6xy/(3y^2 )=100x^2y^2/( )
【2】约分
-18xy/27x^2y^2=
-24n^2m^3/16n^3m^2=
12(x+y)^2/20(x+y)(x+2y)
【4】判断是否是最简分式,不是的请化简
18/45xy
x+16/2x+16
25xy/15xz