Question #25791

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Answer 1 · 2018-01-19T12:54:56

One popcorn costs $6.425 and one drink costs $1.8. In total both cost $8.225.

If we assign variables to the popcorn and the drinks...
Popcorn = $x$ $x$
Drink = $y$ $y$

First equation:
$2 x + 3 y = 18.25$ $2x+3y=18.25$
Second equation:
$4 x + y = 27.50$ $4x+y=27.50$

Now you just need to solve the simultaneous questions. Personally my favourite way of doing it is substitution. See below:

From $4 x + y = 27.50$ $4x+y=27.50$ , $y = 27.50 - 4 x$ $y=27.50-4x$ .

I can substitute this into the first equation replacing $y$ $y$ :
$2 x + 3 (27.50 - 4 x) = 18.25$ $2x+3(27.50-4x)=18.25$

I then solve for $x$ $x$ :
$x = 6.425$ $x=6.425$

Then solve for $y$ $y$ :
$y = 27.50 - 4 (6.425)$ $y=27.50-4(6.425)$
$y = 1.8$ $y=1.8$

The price of one popcorn and one drink is thus $6.425 + 1.8 = 8.225$ $6.425+1.8=8.225$