What is the value of 2(5b - 7) in terms of y if b = 3y ?

One side of a rectangle is 7 feet shorter than seven times the other side. find the length of the shorter side if we also know that the perimeter of the rectangle is 306 feet.

X2 + y 2 = 36 x + y = 6 solve the system of equations.

An investment decreases in value by 30% in the first year and decreases by 40% in the second year. what is the percent decrease in percentage in the investment after two years