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Stella buys 6 tacos and 4 enchiladas for 52 dollars. Eliana buys 7 tacos and 9 enchilladas for 78 dollars.

Part A: Enter the cost for one taco.
Part B: Enter the cost for one enchilada.

User Nikolay Kovalenko
by
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1 Answer

20 votes
20 votes

Answer:

Let tacos be x and enchiladas be y

6 tacos + 4 enchiladas = 52

becomes

6x+4y=52

^^that's our first equation

Now, the second equation

7 tacos + 9 enchiladas = 78

7x+9y = 78

^^^that's our second equation

Isolate y in the first equation:

6x+4y=52

4y=52-6x

y = (52-6x)/4

^^^Let's call this equation 3

Now, sub-in equation 3 into equation 2

*replace the y*

Equation 2: 7x+9y = 78

Sub-in

7x+ 9 ( (52-6x)/4) = 78

Do some algebra (get your x terms on one side) and you will find your x value

7x + 117 - 13.5x = 78

(7x-13.5x) = 78-117 *get your x terms on one side

x=6

That's the cost of one taco.

Now, find y. Pick an equation (1,2 or 3). Let's pick 3 since y is already isolated.

All you do is plug in your x value.

Equation 3: y = (52-6x)/4

y= (52 -6(6))/4

...

You should be able to solve this on your own

Explanation:

:)) You can solve for y now

User Smingerson
by
2.5k points
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