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.

5a - 5x = -7a + 8x - 9
5a = -7a + 8x - 9 + 5x
5a + 7a = 8x - 9 + 5x
12a = 13x - 9
a = \( \frac{13x - 9}{12} \)
a = \( \frac{13x}{12} \) + \( \frac{-9}{12} \)
a = 1\(\frac{1}{12}\)x - \(\frac{3}{4}\)

To multiply binomials, use the FOIL method. FOIL stands for First, Outside, Inside, Last and refers to the position of each term in the parentheses:

(y + 3)(y + 4)
(y x y) + (y x 4) + (3 x y) + (3 x 4)
y² + 4y + 3y + 12
y² + 7y + 12

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 -10 as well and sum (Inside, Outside) to equal -3. For this problem, those two numbers are -5 and 2. Then, plug these into a set of binomials using the square root of the First variable (y²):

y² - 3y - 10
y² + (-5 + 2)y + (-5 x 2)
(y - 5)(y + 2)

An isosceles triangle has two sides of equal length. An equilateral triangle has three sides of equal length. In a right triangle, two sides meet at a right angle.

A line segment is a portion of a line with a measurable length. The midpoint of a line segment is the point exactly halfway between the endpoints. The midpoint bisects (cuts in half) the line segment.