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