Linear Equation Project 2nd Trimester 8th GradeSample by Mrs. Nagel

I have $50 to spend at the movies. I want to buy soda and popcorn to share with my friends. How much of each can I buy with my $50.

Soda is $5 a cup and a large bag of popcorn is $10.

Standard form of a line ax + by =cSoda = a= $5Popcorn = b= $10

5x + 10y = 50

5x + 10y = 50-5x -5x 10y = -5x + 50

10y = -5x + 5010 10 10

y = -1/2 x + 5

slope y-intercept

If I buy 1 soda how many popcorns can I buy?

5x + 10 y = 50 5(1) + 10 y = 50 5 + 10y = 50-5 -5

10y = 4510 10

Y = 4.5

If I buy 2 sodas, how many popcorns can I buy?

5x + 10y = 50

5(2) + 10 y = 50

10 + 10y = 50-10 -1010y = 40Y = 4

If I buy 4 sodas, how many popcorns can I buy?

5x + 10 y = 50

5 (4) = 10 y = 5020 + 10y = 50-20 -2010y = 30Y = 3

If I buy six sodas, how many popcorns can I buy?

5x + 10y = 50

5(6) + 10y = 50

30 + 10y = 50

-30 -30

10y = 20Y = 2

If I buy 10 sodas, how many popcorns can I buy?

5x + 10y = 50

5(10) + 10y = 50

50 + 10 y = 50-50 -5010y = 0Y = 0

How many popcorns can I buy if I don’t buy any sodas?

5x + 10y = 50

5 (0) + 10y = 50

0 + 10y = 50

10y = 50

Y = 5

TABLE OF VALUES

X Y0 510 02 31 4.54 36 2

54321

1 2 3 4 5 6 7 8 9 10

5X + 10Y = 50 5X + 10 (0)= 50

5(0) + 10Y = 50 5X = 500 + 10Y = 50 X = 10Y = 5 (10, 0)(0,5) Y- INTERCEPT X-INTERCEPT

Rate of Changey2-y1x2-x1

(10, 0) (0, 5)5-0

0-10

- 1/2

Well, I decided that I should buy each one of my friends their own popcorn and their own drink. I also decided to buy myself two different drinks, so I actually purchased 4 drinks and 3 popcorns.

It was sure a good day at the movies.