Ryan is 5 feet tall. His shadow is 9 feet long and the shadow of a building is 36 feet long. How tall is the building? Draw two similar triangles and then determine the height of the building.

Awater holding tank measures 105 m long, 50 m wide, and 8 m deep. traces of mercury have been found in the tank, with a concen- tration of 60 mg/l. what is the total mass of mercury in the tank? answer in units of kg.

True or false: the graph of y=f(bx) is a horizontal compression of the graph y=f(x) if b< 1

1) prove that 731^3−631^3 is divisible by 100 2) prove that 99^3−74^3 is divisible by 25