To solve this equation, replace the variables with the values given and then solve the now variable-free equation. (Remember order of operations, PEMDAS, Parentheses, Exponents, Multiplication/Division, Addition/Subtraction.)

5a(a - x)
5(6)(6 - 3)
5(6)(3)
(30)(3)
90

Parallel lines are lines that share the same slope (steepness) and therefore never intersect. A transversal occurs when a set of parallel lines are crossed by another line. All of the angles formed by a transversal are called interior angles and angles in the same position on different parallel lines equal each other (a° = w°, b° = x°, c° = z°, d° = y°) and are called corresponding angles. Alternate interior angles are equal (a° = z°, b° = y°, c° = w°, d° = x°) and all acute angles (a° = c° = w° = z°) and all obtuse angles (b° = d° = x° = y°) equal each other. Same-side interior angles are supplementary and add up to 180° (e.g. a° + d° = 180°, d° + c° = 180°).

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 16 as well and sum (Inside, Outside) to equal 10. For this problem, those two numbers are 2 and 8. Then, plug these into a set of binomials using the square root of the First variable (y²):

y² + 10y + 16
y² + (2 + 8)y + (2 x 8)
(y + 2)(y + 8)

To solve this equation, isolate the variable for which you are solving (a) on one side of the equation and put everything else on the other side.

3a - x = -9a - 5x + 2
3a = -9a - 5x + 2 + x
3a + 9a = -5x + 2 + x
12a = -4x + 2
a = \( \frac{-4x + 2}{12} \)
a = \( \frac{-4x}{12} \) + \( \frac{2}{12} \)
a = -\(\frac{1}{3}\)x + \(\frac{1}{6}\)

To solve this equation, repeatedly do the same thing to both sides of the equation until the variable is isolated on one side of the > sign and the answer on the other.

9y + 2 > 1 - 4y
9y > 1 - 4y - 2
9y + 4y > 1 - 2
13y > -1
y > \( \frac{-1}{13} \)
y > -\(\frac{1}{13}\)