The cost of downloading $\displaystyle{x}\usepackage{cmbright}\Huge\$ songs in a month from TunesRUs is $\displaystyle{12}+{5}{x}\usepackage{cmbright}\Huge\$ dollars and the cost of downloading $\displaystyle{x}\usepackage{cmbright}\Huge\$ songs in a month from Music4U is $\displaystyle{7}{x}\usepackage{cmbright}\Huge\$ dollars. The graphs of $\displaystyle{y}={12}+{5}{x}\usepackage{cmbright}\Huge\$ (the TunesRUs function) and $\displaystyle{y}={7}{x}\usepackage{cmbright}\Huge\$ (the Music4U function) are shown below. Notice that the two graphs intersect when $\displaystyle{x}={6}\usepackage{cmbright}\Huge\$ (with a common $\displaystyle{y}\usepackage{cmbright}\Huge\$ -value of 42), TunesRUs costs more when $\displaystyle{x}<{6}\usepackage{cmbright}\Huge\$ , and TunesRUs costs less than Music4U when $\displaystyle{x}>{6}\usepackage{cmbright}\Huge\$ .

$\displaystyle{y}={7}{x}\usepackage{cmbright}\Huge\$ (Music 4U)

$\displaystyle{y}={12}{x}+{5}\usepackage{cmbright}\Huge\$ (TunesRUs)