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.

5a + 9a = 14a

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, \(c = \sqrt{a + b}\)

You need to find the value of a so solve the first equation in terms of z:

6a + z = -3
z = -3 - 6a

then substitute the result (-3 - 6a) into the second equation:

-6a - 9(-3 - 6a) = -1
-6a + (-9 x -3) + (-9 x -6a) = -1
-6a + 27 + 54a = -1
-6a + 54a = -1 - 27
48a = -28
a = \( \frac{-28}{48} \)
a = -\(\frac{7}{12}\)

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.

9a - 5a = 4a

A quadrilateral is a shape with four sides. The perimeter of a quadrilateral is the sum of the lengths of its four sides.