Question

Janelle bought a notebook and three mechanical pencils for $4.75, while Sharai bought two notebooks and one mechanical pencil for $3.25. What is the cost of a mechanical pencil?

Answer 1

mechanical pencil costs $1.25 each

Explanation:

First, lets define our variables:

notebook = n

mechanical pencil = p

Next, we need to set up two equations using the information given:

n + 3p = 4.75

2n + p = 3.25

Next, lets take the first equation and solve for n.

n+ 3p = 4.75

n = 4.75 - 3p

Now we can replace "n" in the second equation with "4.75 - 3p".

2n + p = 3.25

2(4.75 - 3p) + p =3.25

9.5 - 6p + p = 3.25

9.5 - 5 p = 3.25

9.5 = 5p + 3.25

5p = 6.25

p = 1.25

Finally, we can go a step further and solve for "n" by plugging "p" back into the second formula:

n = 4.75 - 3(1.25)

n = 1.0

I hope this helps!

-TheBusinessMan