A computer store buys a computer system at a cost of $370.80. The selling price was first at $ 618, but then the store advertised a 20 % markdown on the system. Answer parts a and b.

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?

Graph the equationy= x+3[tex]y = x + 3[/tex]

What are the excluded values? m+5/mn+3m