Chapter 5 - Section 5.1 - Ratios, Rates, and Proportions - Exercises - Page 216: 12b

$x\approx4.65$ or $-3.65$

$\frac{x+1}{3} = \frac{5}{x-2}$ $(x+1)(x-2) = 5\times3$ $x^{2}-x-2 = 15$ $x^{2}-x-17 = 0$ $x=\frac{-(-1)\pm\sqrt {(-1)^{2}-4(1)(-17)}}{2(1)}$ $x=\frac{1\pm\sqrt {69}}{2}$ $x\approx4.65$ or $-3.65$