Answer:
x = 1; y = 2
Explanation:
To find x:
Multiply (5x+y=7) by 3 to get the y's in both equation the same, and you will get 15x+3y=21.
Now the y's cancel out. Subtract the remaining equations: (15x=21) - (6x=12) and you get 9x = 9. Divide everything by 9 and you get x=1.
To find y:
You can substitute 1 for x in either equation. I will use (5x+y=7).
Substitute the 1 for x: 5(1)+y=7
Simplify: 5+y=7
Put like terms on the same side by subtracting 5 from both sides: y=2
Check:
6(1) + 3(2) = 12
6 + 6 = 12
12 = 12 - this is right
5(1) + (2) = 7
5 + 2 = 7
7 = 7 - this is right