solve the simultaneous equation: 3x+y=7, 2x+4y=8

First, we need to remove one of the variables from one of the equations. In this case, we multiply the first equation by 4 to give 12x+4y=28.Then minus the 2nd equation from this to give 10x+0y=20.Now divide by 10 to get x=2.Substitute this into either of the original equations to get y.eg: (x=2) 3x+y=7, so 6+y=7, so y=1.Substitute this into the other equation along with x to check:2x+4y when x=2 and y=1 gives 8, so this is correct.
1). 3x+y=7 (x4)2). 2x+4y=8 (x1)
12x+4y=28 (-)2x+4y=8
10x=20so x=2
32+y=7so y=1
22+4*1=8 is true, so x=2 and y=1