[tex] \frac{5x}{2} - \frac{3x}{4} = 10 \frac{1}{2} \\ [/tex]
[tex] \frac{5x}{2} - \frac{3x}{4} = \frac{21}{2} \\ [/tex]
Multiply both sides by 4
[tex]4 \times ( \frac{5x}{2} - \frac{3x}{4} ) = 4 \times \frac{21}{2} \\ [/tex]
[tex]10x - 3x = 42[/tex]
[tex]7x = 42[/tex]
Divide both sides by 7
[tex] \frac{7x}{7} = \frac{42}{7} \\ [/tex]
[tex]x = 6[/tex]