Answer:
Madelyn bought 2 bags of popcorn and 8 pretzels.
Step-by-step explanation:
Madelyn and her children went into a movie theater and she bought $39 worth of bags of popcorn and pretzels. Each bag of popcorn costs $6.50 and each pretzel costs $3.25. She bought 4 times as many pretzels as bags of popcorn. Graphically solve a system of equations in order to determine the number of bags of popcorn, x,x, and the number of pretzels, y,y, that Madelyn bought.
\underline{\text{Variable Definitions:}}
Variable Definitions:
x=
x=
\,\,\text{the number of bags of popcorn}
the number of bags of popcorn
y=
y=
\,\,\text{the number of pretzels}
the number of pretzels
One bag of popcorn costs $6.50, so xx bags of popcorn cost 6.50x.6.50x. One pretzel costs $3.25, so yy pretzels cost 3.25y.3.25y. The total 6.50x+3.25y6.50x+3.25y equals \$39:$39:
6.50x+3.25y=39
6.50x+3.25y=39
Since Madelyn bought 4 times as many pretzels as bags of popcorn, there are more pretzels, so if we multiply 4 by the number of bags of popcorn, we will get the number of pretzels, meaning yy equals 4x.4x.
y=4x
y=4x
\underline{\text{Write System of Equations:}}
Write System of Equations:
6.50x+3.25y=
6.50x+3.25y=
\,\,39
39
y=
y=
\,\,4x
4x
\underline{\text{Solve for }y\text{ in each equation:}}
Solve for y in each equation:
6.50x+3.25y=39
3.25y=−6.50x+39
3.25
3.25y
=
3.25
−6.50x+39
y=−2x+12
y=4x
0
the number of bags of popcorn
the number of pretzels
x
y
(2, 8)
0
the number of bags of popcorn
the number of pretzels
The xx variable represents the number of bags of popcorn and the yy variable represents the number of pretzels. Since the lines intersect at the point \left(2, 8\right)(2,8) we can say:
Madelyn bought 2 bags of popcorn and 8 pretzels.
