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).

The entire length of this line is represented by AD which is AB + BD:

AD = AB + BD

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.

2x - 1 < \( \frac{x}{-7} \)
-7 x (2x - 1) < x
(-7 x 2x) + (-7 x -1) < x
-14x + 7 < x
-14x + 7 - x < 0
-14x - x < -7
-15x < -7
x < \( \frac{-7}{-15} \)
x < \(\frac{7}{15}\)

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.

4a⁴ - 5a⁴ = -1a⁴

Perimeter is equal to the sum of the four sides:

p = a + b + c + d
p = 3 + 5 + 2 + 5
p = 15