Which expression is not equivalent to -3x + 24? Select all that apply. A. -3(x - 8)
B. -(3x + 24)
C. 3/2(-2x + 16)
D. -1/3( 9x + 8)
E. 6(-1/2x - 4)
F. 8(-3/8x + 3)

Here is their argument. given the obtuse angle x, we make a quadrilateral abcd with ∠dab = x, and ∠abc = 90◦, and ad = bc. say the perpendicular bisector to dc meets the perpendicular bisector to ab at p. then pa = pb and pc = pd. so the triangles pad and pbc have equal sides and are congruent. thus ∠pad = ∠pbc. but pab is isosceles, hence ∠pab = ∠pba. subtracting, gives x = ∠pad−∠pab = ∠pbc −∠pba = 90◦. this is a preposterous conclusion – just where is the mistake in the "proof" and why does the argument break down there?

Scores on a university exam are normally distributed with a mean of 78 and a standard deviation of 8. the professor teaching the class declares that a score of 70 or higher is required for a grade of at least “c.” using the 68-95-99.7 rule, what percentage of students failed to earn a grade of at least “c”?

Alice is paying her bill at a restaurant. but tax on the cost of a male is 5%. she decides to leave a tip 20% of the cost of the meal plus the tax