3(x+4y)-4x=2(2x+y)
7(x-5y)+6x=3(x+4y)+27
---
3x+12y-4x=4x+2y
7x-35y+6x=3x+12y+27
---
-x+12y=4x+2y
13x-35y=3x+12y+27
---
-x+12y-4x-2y=0
13x-3x-35y-12y=27
---
-5x+10y=0
10x-47y=27
---
x-2y=0
10x-47y=27
---
x=2y
10.2y-27y=27
---
x=2y
20y-27y=27
---
x=2y
-7y=27
---
x=2y
y=-27/7
---
x=-54/7
y=-27/7
========