20 PTS HURRYA blackboard has an area of 28ft2 and a perimeter of 22 ft. What are the dimensions of the board?

2[L + W] =22L*W = 28W = 28/L sub this in the first equationSolve for L:
2 (L + 28/L) = 22Divide both sides by a constant to simplify the equation.Divide both sides by 2:L + 28/L = 11Write the left hand side as a single fraction.Bring L + 28/L together using the common denominator L:(L^2 + 28)/L = 11Multiply both sides by a polynomial to clear fractions.Multiply both sides by L:L^2 + 28 = 11 LMove everything to the left hand side.Subtract 11 L from both sides:L^2 - 11 L + 28 = 0Factor the left hand side.The left hand side factors into a product with two terms:(L - 7) (L - 4) = 0Find the roots of each term in the product separately.Split into two equations:L - 7 = 0 or L - 4 = 0Look at the first equation: Solve for L.Add 7 to both sides:L = 7 or L - 4 = 0Look at the second equation: Solve for L.Add 4 to both sides:L = 7       or L = 4         and        W=4      or W = 7