Question

Ahmed is taking orders for lunch. A slice of pizza cost $2.50 and a chicken sandwich cost $3.50. He collects $21.50 for the group of 7. let x= number of pizza orders. Let y= number of chicken orders.
Assuming each person only orders one item. how many people order the chicken sandwich?

Answer 1

What is x + y = ?

Answer 2

3.50x+2.50y=21.50?

Answer 3

You've got the right idea, but you switched the prices.
x = number of pizza slices. Slice costs $2.50
y = number of chicken sandwiches. Sandwich costs $3.50
x goes with 2.50 and y goes with 3.50

Answer 4

2.50x+3.50y=21.50, so I solve for y?

Answer 5

This is one equation. You have two variables, so you need a second equation.
That's why I asked what is x plus y equal to?

Answer 6

Oh.
So.
7 x $2.50 = $21.50
1 x $3.50 = $3.50

Answer 7

I'm confused.

Answer 8

You wrote the equation below, and it is good.
2.50x+3.50y=21.50

Now you need one more equation that connects x and y.
There is a piece of information the problem gave that will allow you to write a second equation that also has x and y.

Answer 9

There are 7 people placing orders.
Each person only orders one order, either a slice or a sandwich.
So we know that only 7 orders will be placed.
There will be x orders of pizza and y orders of chicken sandwich.
The total number of orders is 7, so
x + y = 7

Answer 10

Now you have two equations with two unkowns. Now you can solve the system of equations for x and y.

Answer 11

y=4
x=3

Answer 12

right?

Answer 13

2.50x+3.50y=21.50
x + y = 7
This system of equation needs to be solved.
Take the second equation and solve it for x:
x = 7 - y

Now insert what x is equal to, 7 - y, into x of the first equation:
2.5(7 - y) + 3.5y = 21.5
17.5 - 2.5y + 3.5y = 21.5
y + 17.5 = 21.5
y = 4

x + y = 7
x + 4 = 7
x = 3

Answer: 3 slices & 4 sandwiches

Answer 14

You are correct