This is going to take a while. First, set up equations for both Jaidee and Eugene. Jaidee's equation is

s represents the cost of the small box of tangerines and

represents the cost of the large box of tangerines. Eugene's equation is

. Next, I'm going to solve the equations through elimination. Multiply -2 by the first equation and multiply 5 by the second equation.

Do the same for the second equation.

. Then add

This gives you

. Next divide on both sides

this will give you

. So you know what

is. Next, plug in

to

which looks like this

. Solve 10s+500=600 = 10s+500-500=600-500 =10s=100 = 10s/10=100/10 = s=10 . So each box of small tangerines costs $10 and each box of large tangerines cost $20.