Ava takes 4 guitar lessons per month.
The monthly cost is $90.
The 4 lessons have a total cost of $90. If you want to know how much if for just 1 lesson, what you have to do is divide the total cost that is $90, by the number of lessons that are 4 each month, thus:
[tex]\begin{gathered} \text{Cost per lesson=}\frac{90}{4} \\ \text{Divide both the numerator and denominator by 2 to simplify:} \\ \frac{90/2}{4/2}=\frac{45}{2} \end{gathered}[/tex]
And you can simplify it again, 45/2 means the half of 45, since it is not an integer number, you can rewrite 45 as 40+5, then:
[tex]\begin{gathered} \frac{40+5}{2}\text{ applying the properties of fractions:} \\ \frac{40}{2}+\frac{5}{2} \end{gathered}[/tex]
Now, 40/2 is equal to 20, and 5/2 is equal to 2.5 (this is the half of 5), thus:
[tex]\frac{40}{2}+\frac{5}{2}=20+2.5=22.5[/tex]
The answer is option D. $22.50
