The cost of 1 pen and 4 pencils is $2.70. If each pen costs 5 times as much as each pencil, how much do 7 pens and 5 pencils cost?

The base of a triangle exceeds the height by 7 centimeters. if the area is 400 square centimeters, find the length of the base and the height of the triangle.

Me n o w. i need t h i s. 10 points

David estimated he had about 20 fish in his pond. a year later, there were about 1.5 times as many fish. the year after that, the number of fish increased by a factor of 1.5 again. the number of fish is modeled by f(x)=20(1.5)^x. create a question you could ask that could be answered only by graphing or using a logarithm.