Answer:
The pencils cost $0.4 each and the folders $0.5.
Step-by-step explanation:
Since Sally bought six pencils and three folders for $3.9. We have the following expression:
6*penchils + 3*folders = 3.9
And since Henry bought two pencils and five folders for $3.3. We have the following expression:
2*pencils + 5*folders = 3.3
The system of equations is given by:
6*pencils + 3*folders = 3.9
2*pencils + 5*folders = 3.3
In order to solve it we will multiply the second equation by -3 and sum both equations:
6*pencils + 3*folders = 3.9
-6*pencils - 15*folders = -9.9
We have:
-12*folders = -6
folders = 0.5
2*pencils + 5*0.5 = 3.3
2*pencils + 2.5 = 3.3
2*pencils = 3.3 - 2.5
2*pencils = 0.8
pencils = 0.8/2 = 0.4
The pencils cost $0.4 each and the folders $0.5.
