Answer: I not super sure, but I think you are supposed to put the equations on each side of the table. Your end result should be 2x to the second -5x-3.
Step-by-step explanation:
The total angle sum of a triangle is 180°
As such, 180= 78 + 2s +4s
102= 6s
s=17

notice, that, pure juice is 100% juice, dohhh, thus 100/100 = 1.00
50% is 50/100 or 0.50 in decimal format
so..... whatever those two quantities amount to, that is, the 50% and pure juice, or (4)(0.50) + (x)(1.00)
they will equal the mixture desired 60% juice, or 0.60, namely (4+x)(0.60)
thus (4)(0.50) + (x)(1.00) = (4+x)(0.60)
solve for "x"