The amount of money Calvin and Sasha have, is an illustration of equivalent expressions.
Calvin has exactly 13 quarters
From the question, we have:
[tex]\mathbf{Calvin = 0.25Q}[/tex]
[tex]\mathbf{Sasha = 0.05N + 0.01P + 0.10D}[/tex]
Calvin has the same number of quarters as Sasha has dimes.
So, we have:
[tex]\mathbf{Q = D}[/tex]
Sasha has $1.95 in coins that are not dimes.
So, we have
[tex]\mathbf{0.05N +0.01P = 1.95}[/tex]
They have the same amount of money i.e.
[tex]\mathbf{Calvin = Sasha}[/tex]
This gives
[tex]\mathbf{0.25Q = 0.05N + 0.01P + 0.10D }[/tex]
Substitute [tex]\mathbf{0.05N +0.01P = 1.95}[/tex]
[tex]\mathbf{0.25Q = 1.95 + 0.10D }[/tex]
Substitute [tex]\mathbf{Q = D}[/tex]
[tex]\mathbf{0.25Q = 1.95 + 0.10Q }[/tex]
Collect like terms
[tex]\mathbf{0.25Q -0.10Q= 1.95 }\\[/tex]
[tex]\mathbf{0.15Q= 1.95 }[/tex]
Divide both sides by 0.15
[tex]\mathbf{Q= 13 }[/tex]
Hence, Calvin has exactly 13 quarters
Read more about equivalent expressions at:
https://brainly.com/question/15715866
