## Geometry: Common Core (15th Edition)

$x = \frac{34}{7}$
A proportion takes the following form: $\frac{a}{b} = \frac{c}{d}$, where $a$ and $d$ are the extremes and $b$ and $c$ are the means. In this exercise, $a = 5$, $b = 7$, $c = x - 2$, and $d = 4$. The extremes are $5$ and $4$. The means are $7$ and $x - 2$. Let's solve for $x$: $\frac{5}{7} = \frac{x - 2}{4}$ Use the cross products property to get rid of the fractions: $7(x - 2) = 20$ Use the distributive property on the left side of the equation: $7x - 14 = 20$ Add $14$ to each side of the equation to move constants to the right side of the equation: $7x = 34$ Divide each side by $7$ to solve for $x$: $x = \frac{34}{7}$