When looking at a rectangular prism, we know that Volume = length * width * height
If we are given that the volume of the prism is 280 cubic meters (m^3), the length is 8 meters, and the width is 7 meters, we can fill in our equation.
280 = 8 * 7 * height
280 = 56 * height
Because we are solving for the height, we divide both sides by 56
280/56 = height
height = 5 meters
When the X term is one, and doesn't have a leading coefficient, then you can factor it using the box and diamond method. look up videos on Khan Academy of the box and diamond method for solving trinomials. For number 9, you have a difference of squares. That means you can factor to just 2 terms. (x+4)(x-4) this works because 16 has an easy square root, and the sign in between is a negative(difference)