SOLUTION: Theresa sold magazine subscriptions with three prices: $12, $13, and $22. She sold 1 fewer of the $12
subscriptions than of the $13 subscriptions and sold a total of 40 subscripti
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Human-and-algebraic-language
-> SOLUTION: Theresa sold magazine subscriptions with three prices: $12, $13, and $22. She sold 1 fewer of the $12
subscriptions than of the $13 subscriptions and sold a total of 40 subscripti
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Question 582513: Theresa sold magazine subscriptions with three prices: $12, $13, and $22. She sold 1 fewer of the $12
subscriptions than of the $13 subscriptions and sold a total of 40 subscriptions. If her total sales
amounted to $643, how many $22 subscriptions did Theresa sell? Answer by josmiceli(19441) (Show Source):
You can put this solution on YOUR website! Let = number of $12 ones she sold
Let = number of $13 ones she sold
Let = number of $22 ones she sold
given:
(1)
(2)
(3)
This is 3 equations and 3 unknowns, so it's solvable
---------
Multiply both sides of (2) by and
subtract (3) from (2)
(2)
(3)
Substitute (1) into this result
and, since
(1)
(1)
(1)
and
(2)
(2)
(2)
(2)
(2)
She sold 15 of the $22 subscriptions
check answer:
(3)
(3)
(3)
(3)
OK
