24. Complementary angles are 90 degrees. If angle A and angle B combine, they form 90 degrees. Therefore, if you subtract 90 degrees from angle A, it will give you angle B. The correct answer is G, y = 90 - x.
25. (5n-2)3n - (5n-2)(n-1)
= (5n-2)(3n-n+1)
= (5n-2)(2n+1)
= 10n^2+n-2, which is D.
26. There were 20+30+110+40 = 200 students surveyed, and 20/200 = 1/10 preferred skating. Out of the 2340 students, we would expect 2340(1/10) = 234 students, which is F.