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 < sign and the answer on the other.

-5z - 4 < -2 + 8z
-5z < -2 + 8z + 4
-5z - 8z < -2 + 4
-13z < 2
z < \( \frac{2}{-13} \)
z < -\(\frac{2}{13}\)

The area of a trapezoid is one-half the sum of the lengths of the parallel sides multiplied by the height:

a = ½(b + d)(h)
a = ½(6 + 7)(3)
a = ½(13)(3)
a = ½(39) = \( \frac{39}{2} \)
a = 19\(\frac{1}{2}\)

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

2c + z = -1
z = -1 - 2c

then substitute the result (-1 - 2c) into the second equation:

-8c - 7(-1 - 2c) = -4
-8c + (-7 x -1) + (-7 x -2c) = -4
-8c + 7 + 14c = -4
-8c + 14c = -4 - 7
6c = -11
c = \( \frac{-11}{6} \)
c = -1\(\frac{5}{6}\)

A right angle measures 90 degrees and is the intersection of two perpendicular lines. In diagrams, a right angle is indicated by a small box completing a square with the perpendicular lines.

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.

2a⁷ + 5a⁷ = 7a⁷