First set up a system of equations and solve.
4x+y=10
x+3y=8
In order to have one variable cancel out, I will multiply the top by -3.
-12x-3y=-30
x+3y=8
____________
-11x=-22
x=2
Then plug the x value into one of the original equations.
(2)+3y=8
3y=6
y=2
Now plug both into the final equation:
5(2)+8(2)/3
(10+16)/3
26/3
8.667 is the answer or 26/3.