You may have divided both sides by $\displaystyle-{35}\usepackage{cmbright}\Huge\$ . That would leave you with $\displaystyle{\left(\frac{{1}}{{7}}\right)}{x}={1}\usepackage{cmbright}\Huge\$ . This would not mean that x is equal to $\displaystyle\frac{{1}}{{7}}\usepackage{cmbright}\Huge\$ .