Solve the following system of equations using elimination: 13x + 5y = 16 2x - 8y = 20

13x + 5y = 16
2x - 8y = 20

Multiply the equations;

13x + 5y = 16 [x2]
2x - 8y = 20 [x13]

26x + 20y = 32
26x - 104y = 260

Reverse the signs on one equation;

26x + 20y = 32
-26x + 104y = -260

'-26x' gets cancelled, leaving;

20y = 32
104y = -260

20y + 104y = 124y
32 - 260 = -228

124y = -228

y = -228 / 124

y = -1.84

Substitute in one equation and find 'x'. 

Hope this helped! :)