Question

patterns in proportional relationships, need help with the graph and the process table, i need to find a algebraic rule that represents the relationship between the number of pizzas, x, and the total cost, y.

Answer 1

Since the cost of each medium pizza is $7, then

Assume that the number of pizzas is x and the total cost is y, then

Multiply x by x to find y

The algebraic rule is

`y=7x`

a) Let us complete the table

x: Process: y

0 0 x 7 = 0 0

1 1 x 7 = 7 7

2 2 x 7 = 14 14

3 3 x 7 = 21 21

4 4 x 7 = 28 28

a) We need to find the cost of 10 pizzas, then

Substitute x by 10 in the algebraic rule

`\begin{gathered} y=7(10) \\ y=70 \end{gathered}`

The cost of the 10 pizzas is $70

b) If you have exactly $84, then substitute y by 84 to find x

`\begin{gathered} y=84 \\ 84=7x \end{gathered}`

Divide both sides by 7 to find x

`\begin{gathered} (84)/(7)=(7x)/(7) \\ 12=x \end{gathered}`

You can buy 12 pizzas buy $84

c) If you buy 0 pizza, then the cost of it is

`\begin{gathered} x=0 \\ y=7(0) \\ y=0 \end{gathered}`

Since zero multiplied by any number give zero

The cost of zero pizza is zero

Because 0 x $7 = $0