Solve the equation 4s^2 + 32s = 60 by completing the square

Iam trying to solve a linear equation for the shoe size of someone 84" tall taking into consideration example 1 is 69" tall with a shoe size of 9 and example 2 is 72 inches tall with a shoe size of 11. i understand that the equation should be y=mx+b and that on the graph the answer is (3,2) but i just don't understand how to create the equation to solve for 84-inches and 60-inches tall questions. after two days, i need .

Factor the polynomial 4x4 – 20x2 – 3x2 + 15 by grouping. what is the resulting expression? (4x2 + 3)(x2 – 5) (4x2 – 3)(x2 – 5) (4x2 – 5)(x2 + 3) (4x2 + 5)(x2 – 3)

The volume, v, of a rectangular prism is determined using the formula, where / is the length, w is the width, and his theheight of the prism. carltren solves for w and writes the equivalent equation w=using this formula, what is the width of a rectangular prism that has a volume of 138.24 cubic inches, a height of 9.6 inches,and a length of 3.2 inches?