Question

Two sandwiches and a juice cost

£3.40. Four sandwiches and three
juices cost £7.20. What is the cost
of a sandwich?

Answer 1

This is basically dependent on linear equation in 2 variables.

First, we write the equations for these down. Here they are:

2 sandwiches and a juice:

2x + y = £3.4

Four sandwiches and three juices:

4x + 3y = £7.2

Now, lets use 1 equation to find the value of x.

Here's how

We take the equation, 4x + 3y = £7.2

4x = 7.2 - 3y

x =
`(7.2 - 3y)/(4)`

Once you found x, plug this value into the other equation.

So you'd get:

2(
`(7.2 - 3y)/(4)`) + y = £3.4

Multiply and you get:

`(7.2 - 3y)/(2)` + y = £3.4

Now, make the denominators same and you get:

`(7.2 - 3y)/(2)` +
`(2y)/(2)` = £3.4

So, you get:

`(7.2-y)/(2)` = £3.4

Bring the 2 to the other side and you get:

7.2 - y = 6.8

y = 7.2 - 6.8 = 0.4

Therefore, 1 sandwich costs £0.4

That's it really :D

Answer 2

the price of a juice is $0.4

Explanation: