An equivalent expression to m+m+m+m that is a product of a coefficient and a variable

Find the number of positive three-digit even integers whose digits are among 9, 8, 7,5, 3, and 1.

Technicians have installed a center pivot, circular irrigator for a farm that covers 25 acres. a.) how long is the irrigation boom (in feet) from the center pivot to its farthest extent? b.) if the irrigation boom makes 4 full revolutions in a day, how many miles does the end of the boom travel in 5 days?

What is the expression equivalent to (3x^2-7)