Phil have 5- $0.37 stamps.
What is unitary method?
The unitary method is a technique for solving a problem by first finding the value of a single unit, and then finding the necessary value by multiplying the single unit value.
Given:
Phil has 12 stamps
These stamps come in two denominations: $0.37 and $0.23
The value of these stamps is $3.46
let x be the $0.37 stamps and y be the $0.23 stamps.
So, the equations are
x + y = 12 => y= 12-x
0.37x + 0.23y = 3.46
Solving
0.37x + 0.23 (12-x) = 3.46
0.37x + 2.76 - 0.23x= 3.46
0.14x= 0.7
x= 0.7/0.14
x=70/14
x=5
Now, y= 12-5 = 7
Hence, Phil have 5- $0.37 stamps.
Learn more about unitary method here: