x/2=3.5
-42-5b=-6(5b-2)-2b
x/6=7
2x=15
x^2-9y-x=2y^2-12y
x+2y-1=0
dy/dx $2e^{2x}$ (2x-4)
3.476/53
3x-4y=25
x^2+y^2=26
3476/53
7y=5y+16
