Jackson runs a farm stand that sells bananas and grapes. Each pound of bananas sells for $1 and each pound of grapes sells for $2.25. Jackson sold 15 more pounds of bananas than pounds of grapes and made $54 altogether. Graphically solve a system of equations in order to determine the number of pounds of bananas sold, x, x, and the number of pounds of grapes sold, yy.

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?

Can someone tell me if this is perpendicular? !

Acredit union pays 5% annual interest, compounded daily, on savings deposits. find the value after one year of $500 deposited in this account. $525.64 $25.64 $20.40 $520.40