Martha M. answered • 11/27/20

Encouraging Tutor Specializing in Math, and Spanish.

Area of the rectangle is L x W=140

We know that L=4+W, so we have to substitute this value to obtain one equation

with just one unknown value;

(4+W) x W=140, solving the equation and making it equal to zero we obtain,

W^{2} + 4W – 140 = 0, using the quadratic formula to solve we get two values for W

One positive and one negative;

W_{1}=10 and W_{2}=-14. Because we are dealing with distances, the value of

cannot be a negative number. Therefore, the value of W is 10. With this, we

can go back to substitute the value of W to find L,

L = 4 + W,

L = 4+ 10 = 14, so the answer is W=10 and L=14