2. A biker rode up a 20 km hill in 2 hours and down the hill in 0.5 hour
without stopping. What was his average speed:
- going up the hill
- going down the hill?
the whole trip?

The equation x2 – 1x – 90 = 0 has solutions {a, b}. what is a + b?

Candy lives in the center of town. her friend darlene lives 28 miles to the east and her friend dana lives 21 miles north. approximately how far do dana and darline live apart ?

Sally deposited money into a savings account paying 4% simple interest per year. the first year, she earned $75 in interest. how much interest will she earn during the following year? show your work and explain your reasoning in the space provided below.