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.

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

-7a + x = -8
x = -8 + 7a

then substitute the result (-8 - -7a) into the second equation:

4a - 3(-8 + 7a) = -5
4a + (-3 x -8) + (-3 x 7a) = -5
4a + 24 - 21a = -5
4a - 21a = -5 - 24
-17a = -29
a = \( \frac{-29}{-17} \)
a = 1\(\frac{12}{17}\)

The coordinate grid is composed of a horizontal x-axis and a vertical y-axis. The center of the grid, where the x-axis and y-axis meet, is called the origin.

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 + 6z = a - 2z - 4
5a = a - 2z - 4 - 6z
5a - a = -2z - 4 - 6z
4a = -8z - 4
a = \( \frac{-8z - 4}{4} \)
a = \( \frac{-8z}{4} \) + \( \frac{-4}{4} \)
a = -2z - 1

Angles around a line add up to 180°. Angles around a point add up to 360°. When two lines intersect, adjacent angles are supplementary (they add up to 180°) and angles across from either other are vertical (they're equal).