we know that
Nata spent [tex]\$28[/tex] on [tex]2[/tex] DVDs
so
by proportion
Find the cost of [tex]5[/tex] DVDs
[tex]\frac{28}{2} \frac{\$}{DVD} =\frac{x}{5} \frac{\$}{DVD}\\ \\2*x=28*5\\ \\x=28*5/2\\ \\x=\$70[/tex]
therefore
The answer Part a) is
The cost of [tex]5[/tex] DVDs is [tex]\$70[/tex]
Part b) Find the unit rate
we know that
Unit Rate is the ratio of two measurements in which the second term is [tex]1[/tex]
so
Find the cost of [tex]1[/tex] DVDs
[tex]\frac{28}{2} \frac{\$}{DVD} =\frac{x}{1} \frac{\$}{DVD}\\ \\2*x=28\\ \\x=28/2\\ \\x=\$14[/tex]
therefore
the unit rate is [tex]14\frac{\$}{DVD}[/tex]
The answer Part b) is
Nata spent her money at the rate [tex]14\frac{\$}{DVD}[/tex]
