Find the error in the calculations below, if there is one:

Line (1): $\displaystyle-\frac{{{5}{x}}}{{4}}-\frac{{7}}{{2}}<-\frac{{3}}{{8}}\usepackage{cmbright}\Huge\$

Line (2): $\displaystyle{10}{x}+{28}<-{3}\usepackage{cmbright}\Huge\$

Line (3): $\displaystyle{10}{x}<-{31}\usepackage{cmbright}\Huge\$

Line (4): $\displaystyle{x}<-\frac{{31}}{{10}}\usepackage{cmbright}\Huge\$

Line (5):