Posted by Chris on .
continued
4c=3d+3 c=d1 i got (6,7)
x=1/2y+3 2xy=6 i got no solution
8x+2y=13 4x+y=11 i got no solution
2xy=4 3x+y=9 i got (13,30)
3x5y=11 x3y=1 i got (7,2)

algebra 
bobpursley,
all correct.