39=5a+15b
146=15a+55b
2x+3x+9=0
3x^2 -2 +5 divided by (x-2)
-8X-4Y=-64; 6X+2Y=33
a+b=a
b+c=7
c=?
4X+2Y=16; 5X-2Y=38
2X-3Y=15; 3X+3Y=40
=(2*(2+2)+(4+4)*2):
X+Y=2/3; X-Y=1/3
24:54 63:?
