A flat rate shipping box is in the shape of a rectangular prism. You estimate that the volume of the box is 350 cubic inches. You measure the box and find that it has a length of 10 inches, a width of 9 inches, and a height of 4.5 inches. Find the percent error. Round your answer to the nearest tenth of a percent

14.4%

L*W*H=V=10*9*4.5=405 in^3.

that is 50.5 in^3 over the estimate, or 14.4%

the difference of two squares is a special form that has a factorization worth memorizing.

a² - b² = (a - b)(a + b)

your equation can be factored as

x² - 16 = 0

(x - 4)(x + 4) = 0

the zero product rule tells you the solutions are the values of x that make these factors zero: x=4, x=-4.