Doing this will result in two equations with the term $\displaystyle{5}{x}\usepackage{cmbright}\Huge\$ . This could be helpful, but because you really need to get opposite variable terms in the two equations, you will then have to multiply one equation by $\displaystyle-{1}\usepackage{cmbright}\Huge\$ . After you have performed these two multiplications you will also have terms with fractions. However, it is possible to produce opposite variable terms, and no fractions, with just one multiplication.