Use mental math to approximate what a 15% tip would be for a bill of $31.99.

5. which description does not guarantee that a quadrilateral is a squar ajo is a parallelogram with perpendicular diagonals 0% has all sides congruent and all angles congruent o has all right angles and has all sides congruent 10% is both a rectangle and a rhombus 30%

You are standing next to a really big circular lake. you want to measure the diameter of the lake, but you don't want to have to swim across with a measuring tape! you decide to walk around the perimeter of the lake and measure its circumference, and find that it's 400\pi\text{ m}400? m. what is the diameter dd of the lake?

4. bob solved the inequality problem below incorrectly. explain his error and redo the problem showing the correct answer. −2x + 5 < 17 −2x + 5-5 < 17-5 -2x/-2 < 12/-2 x < -6