Substitution Method
posted by Dawn .
Please help me solve:
yx=5
2x2y=10
&
5X+6y=14
3y+x=7

The first set cannot be solved, the two lines represented in the equations are parallel, and have no solution.
The second set, the second equation tells us that x= 3y+7, put that in the first equation
5(3y+7)+6y=14
15y+6y=1435 solve for y 
21y=21 21y/21=21/21 y=1