x+4y=5 and x+2y=7

I assume you'd like to find the solution to this system

x+4y =   5 

x+2y =   7              subtracting the second equation from the first, we have

    2y =  -2             divide by 2 on both sides

y = -1

To find x just substitute this y value into either equation...... using the second one, we have

x + 2(-1) = 7

x - 2 = 7     add 2 to both sides

x = 9

So, the solution is (9, -1)