Ronald is calculating the time required to fill the swimming pool at school. He found that it takes 9 minutes to fill the swimming pool with 81 gallons of water. At what rate does the swimming pool fill, in gallons per minute?

Look at arnold's attempt to solve the equation for b: 3b = 12 b = 3 · 12 b = 36 describe the mistake that arnold made.

What is the effect on the graph of the function f(x)=x when f(x) is replaced with -f(x)+4

White shapes and black shapes are used in a game. some of the shapes are circles. while the rest are squares. the ratio of the number of white shapes to the number of black shapes is 5: 11. the ratio of the number of white cicrles to the number of white squares is 3: 7. the ratio of the number of black circles to the number of black squres is 3: 8. work out what fraction of all the shapes are circles.