Question

Paul paid $8.70 for 5 Notebooks and 2 Binders. Billy spent $11.40 on 3 Notebooks and 4 Binders.

a. Type your system of equations.

b. How much is each Notebook and each Binder?

Answer 1

B=2.20

N=0.90

Explanation:

5N+2B=8.70

3N+4B=11.40

15N+6B=26.1

15N+20B=57

-14B= -30.9

B=2.20

Answer 2

1 Notebook is approximately $0.86

1 Binder is approximately $2.21

Explanation:

let N is the price of a notebook and B is the price of the binder

Paul paid $8.70 for 5 Notebooks and 2 Binders

5N + 2B = 8.70 Eq.1

Billy spent $11.40 on 3 Notebooks and 4 Binders.

3N + 4B = 11.40 Eq.2

multiply Eq.1 by -2

5N + 2B = 8.70

-2(5N + 2B = 8.70)

-10N - 4B = -17.40 Eq.3

add Eq. 2 and Eq.3

3N + 4B = 11.40

-10N - 4B = -17.40

________________

-7N = -6

N = 0.85714...

substitute N = 0.85714... to any of the equations to get B

5N + 2B = 8.70

5(0.85714) + 2B = 8.70

4.2857... + 2B = 8.70

2B = 4.41428....

B = 2.20714....