Step-by-step explanation:
since we need to multiply only one equation with something, elimination might be a good method here. we bring both equations to 4x terms and then subtract the second from the first equation :
4x + 2y = 6
- 4x - 12y = 20
-----------------------
0 14y = -14
y = -1
=> e.g. in the second original equation
x - 3×-1 = 5
x + 3 = 5
x = 2
