Solving linear equations with variables on both sides

How to turn a word problem into an equation?
• ex. 1: "revenue" problem
• ex. 2: "area" problem

Find the solution.
1. $- 3.4x = 6.3 - 3.7x$
2. $\frac{3}{7} + \frac{5}{7}x = \frac{1}{3}x$
3. $0.42x = - 0.3x - 2.67$
4. $\frac{5}{6}\left( {x + 3} \right) = \frac{1}{2}x$
5. $2\frac{3}{8}x = \frac{1}{4}\left( {2 - x} \right)$
Solve.
1. $3.61 + 0.25x = 0.11 - 1.23x$
2. $20.13 - 11.6x = 3.7 + 15.2x$
3. $- \frac{5}{6}x + 3 = 2 - \frac{1}{6}x$
4. $2\frac{1}{2}x - \frac{7}{2} = 3\frac{1}{4}x + \frac{3}{4}$
Yesterday, Mary biked to school from home at 9 km/h. Today, she walked to school from home at 3.75 km/h. It took her 37 minutes to go to school on both days altogether.
1. How long did it take Mary to bike to school?
2. How far is Mary's home to school?