Now1：x/3=y/3=z/2且xy+yz+zx=99,则2x^2+12y^2+9z^2=?2：（12x^m+1y^n-1-16x^my^n-4x^m-1y^n-1)÷（-4x^m-1y^n-1)==》化简

Question

Now
1：x/3=y/3=z/2且xy+yz+zx=99,则2x^2+12y^2+9z^2=?
2：（12x^m+1y^n-1-16x^my^n-4x^m-1y^n-1)÷（-4x^m-1y^n-1)==》化简

Answer 1

第一题
设x/3=y/3=z/2= t
所以x=y=3t,z=2t
9t^2+6t^2+6t^2=99
t^2=33/7
要求的式子=18t^2+108t^2+36t^2=162t^2=5346/7
第二题
先约个-4
原式=4x^m*y^n- 3x^(m+1)y^(n-1)+x^(m-1)y^(n-1)÷x^(m-1)*y^(n-1)
约x^(m-1)*y^(n-1)
=4xy-3x^2+1