(a)
12+0.72(8)
12+5.76
17.76 qts of antifreeze
(b)
100(12+8(.72))/(12+8)
100(12+5.76)/20
100(17.76)/20
5(17.76)
88.8%
Unless you show a picture, its impossible to solve.
It is impossible to draw a parallelogram with 4 parallel lines (or to draw any quadrilateral with 4 parallel lines, for that matter).
Answer: the answer is right, try putting a $ in front of it, sometimes those programs mess up if you aren't specific
