A line on the coordinate grid can be defined by a slope-intercept equation: y = mx + b. For a given value of x, the value of y can be determined given the slope (m) and y-intercept (b) of the line. The slope of a line is change in y over change in x, \({\Delta y \over \Delta x}\), and the y-intercept is the y-coordinate where the line crosses the vertical y-axis.

The first step to solve a quadratic expression that's not set to zero is to solve the equation so that it is set to zero:

a² - 2a - 53 = -a + 3
a² - 2a - 53 - 3 = -a
a² - 2a + a - 56 = 0
a² - a - 56 = 0

Next, factor the quadratic equation:

a² - a - 56 = 0
(a + 7)(a - 8) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, either (a + 7) or (a - 8) must equal zero:

If (a + 7) = 0, a must equal -7
If (a - 8) = 0, a must equal 8

So the solution is that a = -7 or 8

To factor a quadratic expression, apply the FOIL method (First, Outside, Inside, Last) in reverse. First, find the two Last terms that will multiply to produce -18 as well and sum (Inside, Outside) to equal -7. For this problem, those two numbers are -9 and 2. Then, plug these into a set of binomials using the square root of the First variable (y²):

y² - 7y - 18
y² + (-9 + 2)y + (-9 x 2)
(y - 9)(y + 2)

The formula for circumference is circle diameter x π:

c = πd
c = 13π

A cube is a rectangular solid box with a height (h), length (l), and width (w). The volume is h x l x w and the surface area is 2lw x 2wh + 2lh.