The length of a rectangle is 10 m less than three times the width, and the area of the rectangle is 77 m2. find the dimensions of the rectangle

Let the width be x, the length is then 3x-10

Area of a rectangle is length times width: x (3x-10) = 77 = > 3x^2-10x-77=0

Factor this quadratic equation: (x-7) (3x+11) = 0 =. x=7 or x=-11/3

width cannot be negative, so the only answer is x=7

width is 7m, length is 11m