SOLUTION: Meredith describes to Liza two purchases she made."On Monday, I bought 39 book and 21 CDs for $396. On Tuesday, at the same prices, I bought 52 books and 28 CDs for $518."
Liza
Algebra ->
Equations
-> SOLUTION: Meredith describes to Liza two purchases she made."On Monday, I bought 39 book and 21 CDs for $396. On Tuesday, at the same prices, I bought 52 books and 28 CDs for $518."
Liza
Log On
Question 1016765: Meredith describes to Liza two purchases she made."On Monday, I bought 39 book and 21 CDs for $396. On Tuesday, at the same prices, I bought 52 books and 28 CDs for $518."
Liza thought about the numbers and said "That's impossible!" Is Liza correct? Assume thats all books cost the same amount. Eplain. Answer by ikleyn(52756) (Show Source):
You can put this solution on YOUR website! .
Meredith describes to Liza two purchases she made."On Monday, I bought 39 book and 21 CDs for $396.
On Tuesday, at the same prices, I bought 52 books and 28 CDs for $518."
Liza thought about the numbers and said "That's impossible!" Is Liza correct? Assume that all books cost the same amount. Explain.
----------------------------------------------------------
If you write the system of equations which describes the two purchases, you will see that the coefficients of
the system are proportional with the proportionality coefficient of : = = .
But the ratio of the right sides (that are totals on Monday and Tuesday) is not .
In the terms of the equations, this system is inconsistent.
See the lesson Geometric interpretation of the linear system of two equations in two unknowns in this site.
You may see it (exactly as Liza did) without writing the system explicitly.
