The first step to solve a quadratic equation that's set to zero is to factor the quadratic equation:

y² - 3y - 54 = 0
(y + 6)(y - 9) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (y + 6) or (y - 9) must equal zero:

If (y + 6) = 0, y must equal -6
If (y - 9) = 0, y must equal 9

So the solution is that y = -6 or 9

A rhombus is a parallelogram with four equal-length sides. A square is a rectangle with four equal-length sides.

A quadrilateral is a shape with four sides. The perimeter of a quadrilateral is the sum of the lengths of its four sides.

To multiply monomials, multiply the coefficients (the numbers that come before the variables) of each term, add the exponents of like variables, and multiply the different variables together.

(5a)(9ab) + (8a²)(8b)
(5 x 9)(a x a x b) + (8 x 8)(a² x b)
(45)(a¹⁺¹ x b) + (64)(a²b)
45a²b + 64a²b
109a²b

A cylinder is a solid figure with straight parallel sides and a circular or oval cross section with a radius (r) and a height (h). The volume of a cylinder is π r²h and the surface area is 2(π r²) + 2π rh.