What is the answer to 2+5(8-5)=?

Find the values of y: 3y^3(y^2+ 2/3y)=0

The circumference of a redwood tree trunk is 20π ft, and it is 100 ft tall. what is the approximate volume of the redwood tree trunk? 1,000π ft3 10,000π ft3 4,000π ft3 40,000π ft3

Is the power produced directly proportional to the wind speed, give reasons for your answer?