Chapter 2 - Equations, Inequalities, and Problem Solving - 2.2 Using the Principles Together - 2.2 Exercise Set - Page 94: 45

$x=10$

By combining like terms and using the properties of equality, the solution to the given equation, $ 5-2x=3x-7x+25 $, is \begin{array}{l} -2x-3x+7x=25-5 \\\\ 2x=20 \\\\ x=\dfrac{20}{2} \\\\ x=10 .\end{array} CHECKING: \begin{array}{l} 5-2(10)=3(10)-7(10)+25 \\\\ 5-20=30-70+25 \\\\ -15=-15 \text{ (TRUE)} .\end{array} Hence, the solution is $ x=10 $.