A number has 3 decimal places. It is 7.49 when rounded to the nearest hundredth. What could the number be? Choose 4 correct answers.
a 7.483
b 7.485
C 7.489
d 7.491
e 7.492
f 7.495

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?

Triangle xyz has vertices x(1,3), y(0,0)

The larger of two number is 4 less than twice the smaller number. the sum is 41. find the numbers