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.

5a² - 2a² = 3a²

According to the Pythagorean theorem, the hypotenuse squared is equal to the sum of the two perpendicular sides squared:

c² = a² + b²
c² = 9² + 4²
c² = 81 + 16
c² = 97
c = \( \sqrt{97} \)

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

b² - 81 = 0
(b - 9)(b + 9) = 0

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

If (b - 9) = 0, b must equal 9
If (b + 9) = 0, b must equal -9

So the solution is that b = 9 or -9

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.

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 -7. 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 - 7y + 10
y² + (-5 - 2)y + (-5 x -2)
(y - 5)(y - 2)