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.

4a² - 3a² = 1a²

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

-5c + 2z = 6c - 5z + 5
-5c = 6c - 5z + 5 - 2z
-5c - 6c = -5z + 5 - 2z
-11c = -7z + 5
c = \( \frac{-7z + 5}{-11} \)
c = \( \frac{-7z}{-11} \) + \( \frac{5}{-11} \)
c = \(\frac{7}{11}\)z - \(\frac{5}{11}\)

For parallel lines with a transversal, the following relationships apply:

• angles in the same position on different parallel lines equal each other (a° = w°, b° = x°, c° = z°, d° = y°)
• alternate interior angles are equal (a° = z°, b° = y°, c° = w°, d° = x°)
• 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°)

Applying these relationships starting with y° = 147, the value of d° is 147.

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

A circle is a figure in which each point around its perimeter is an equal distance from the center. The radius of a circle is the distance between the center and any point along its perimeter. A chord is a line segment that connects any two points along its perimeter. The diameter of a circle is the length of a chord that passes through the center of the circle and equals twice the circle's radius (2r).