1. The difference between the product of nine and a number and three times the number. 2. The difference between five times a number and four times the number.

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?

Haruka hiked several kilometers in the morning. she hiked only 66 kilometers in the afternoon, which was 25% less than she had hiked in the morning. how many kilometers did haruka hike in all?

Ican interpret and represent the remainder in division calculations sensibly for the context (eg 27.4 in calculating average height in cm: $27.44 if it represents an amount of money) solve the following problems. 15) the wildlife park charges $25.50 dollars per person to enter their park if the park made $15096 dollars today, how many people entered the park? 16) ms adams plus 2,230 other keen runners ran a marathon: between them they ran 94817.5km. how many km did each competitor run?