初一数学,要详细过程,谢谢.速度ok么
1个回答
1、a/b=2
∴a=2b
a平方-ab+b平方/a平方+b平方=(4b^2-2b^2+b^2)/(4b^2+b^2)=(3b^2)/5b^2=3/5
2 (1)=(a-2)/b(a-2)=1/b
(2)=(x+3)(x-3)/(x-3)^2=(x+3)/(x-3)
(3)=(x+7)(x-7)/(x-7)=x+7
(4)=[(m+n)+2(m-n)][(m+n)-2(m-n)]/(3n-m)
=(m+n+3m-2n)(m+n-2m+2n)/(3n-m)=(4m-n)(3n-m)/(3n-m)=4m-n
(5)=x(3x-6y+1)/(3x-6y+1)=x
(6)=(a-2b-2)^2/(a-2b-2)=a-2b-2
(7)=3ab(2a+3b)/(3b+2a)=3ab
(8)=(x+1/3)(x-1/3)/[3(x-1/3)]=(x+1/3)/3=x/3+1/9
(9)=(2x-1)^2/(1-2x)=-(2x-1)^2/(2x-1)=1-2x
(10)=(3x+y+3x-y)(3x+y-3x+y)/2(2x-y)=6x*2y/2(2x-y)=6xy/(2x-y)
