Answer:
$7.56
Step-by-step explanation:
They sell it in $2.25 per kg
Hamburger: cost
1 kg : 2.25
3.4 : 7.56
1 x 3.4= 3.4
so, 2.25 x 3.4= 7.56
a. The first variable is x and the second variable is y.
b. The equations are
and 
Step-by-step explanation:
Step 1:
The first step is to define the variables. The variables can be any two symbols, letters, characters, etc.
Here let the first variable be x and the let the second variable be y.
So the variables are defined as x and y.
Step 2:
The sum of the given variables is 12.
The first variable + the second variable = 12,

The difference between the two variables is 4.
The first variable - the second variable = 4.

Step 3:
If we add both the equations we get,
and 
x = 8 and y = 4.
Answer:
27/40
Step-by-step explanation: