Khan/khan-exercises — Issue #8983: Systems of equations word problems - is this even solvable?
Author: KhanBugz
Created: 2011-12-19 16:20:59+00:00
State: open
Labels: firefox, vista, wrong-or-unclear

Is this system of equations solvable?

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Find the number of teachers and students on the field trips.

Let x equal the number of teachers and y equal the number of students.

The system of equations is:

8x+3.5y=52
24x+10.5y=156

Solve for x and y using elimination.

Multiply the top equation by −3.

−24x−10.5y=−156
24x+10.5y=156

Add the top and bottom equations together.

0y=0

0y0=00

y=8
===========================

where did y=8 come from?

[systems_of_equations_word_problems.html?seed=139&problem=elimination-x](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/systems_of_equations_word_problems.html?seed=139&problem=elimination-x&debug)

[Answer timeline](http://sandcastle.khanacademy.org/media/castles/Khan:master/exercises/systems_of_equations_word_problems.html?seed=139&problem=elimination-x&debug&activity=%5B%5B%22hint-activity%22%2C%220%22%2C1190%5D%2C%5B%22hint-activity%22%2C%220%22%2C1193%5D%2C%5B%22hint-activity%22%2C%220%22%2C1197%5D%2C%5B%22hint-activity%22%2C%220%22%2C1205%5D%2C%5B%22hint-activity%22%2C%220%22%2C1212%5D%2C%5B%22hint-activity%22%2C%220%22%2C1221%5D%5D)

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Mozilla/5.0 (Windows NT 6.0; rv:8.0) Gecko/20100101 Firefox/8.0

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