Find the solution to the system of equations: x + 3y = 7 and 2x + 4y = 8

{ x + 3 y = 7      * ( - 2)
 2 x + 4 y = 8 

{ - 2 x - 6 y = - 14
    2 x + 4 y = 8

             -2 y =  - 6   * ( -1)

 2 y = 6

y = 6 / 2

y = 3

For x :

2 x + 4 y = 8

2 x + 4 * ( 3) = 8

2 x + 12 = 8

2 x = 8 - 12

2 x = - 4

x = - 4 / 2

x = - 2

Solution:   x = -2    and  y = 3 

hope this helps!