The Pythagorean theorem defines the relationship between the side lengths of a right triangle. The length of the hypotenuse squared (c²) is equal to the sum of the two perpendicular sides squared (a² + b²): c² = a² + b² or, solved for c, \(c = \sqrt{a + b}\)

An acute angle measures less than 90°, a right angle measures 90°, and an obtuse angle measures more than 90°.

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.

2a + 3a = 5a

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.

9a⁴ - 7a⁴ = 2a⁴

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 equal sign and the answer on the other.

-6c - 7 = \( \frac{c}{-7} \)
-7 x (-6c - 7) = c
(-7 x -6c) + (-7 x -7) = c
42c + 49 = c
42c + 49 - c = 0
42c - c = -49
41c = -49
c = \( \frac{-49}{41} \)
c = -1\(\frac{8}{41}\)