A parallelogram is a quadrilateral with two sets of parallel sides. Opposite sides (a = c, b = d) and angles (red = red, blue = blue) are equal. The area of a parallelogram is base x height and the perimeter is the sum of the lengths of all sides (a + b + c + d).

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.

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.

(7a)(6ab) + (6a²)(6b)
(7 x 6)(a x a x b) + (6 x 6)(a² x b)
(42)(a¹⁺¹ x b) + (36)(a²b)
42a²b + 36a²b
78a²b

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

y² + 8y + 16 = 0
(y + 4)(y + 4) = 0

For this expression to be true, the left side of the expression must equal zero. Therefore, (y + 4) must equal zero:

If (y + 4) = 0, y must equal -4

So the solution is that y = -4

To combine like terms, add or subtract the coefficients (the numbers that come before the variables) of terms that have the same variable raised to the same exponent.

3a + 7a = 10a