Question

Motion Problems - D = R x T
Four pencils and five pens cost $2.00. Three pencils and four pens cost $1.58. Find the coast of the pencil and the cost of the pen.

Answer 1

Let a = cost of pencil
Let b = cost of pen

4a + 5b = 2
3a + 4b = 1.58

Now we have two equations and two unknow.

Answer 2

Can u solve it now

Answer 3

I still need help

Answer 4

We can solve this, by using elimination

Lets call this equation 1) 4a + 5b = 2
Lets call this equation 2) 3a + 4b = 1.58

Multipy equation 1 by (3)
Multipy equation 2 by (-4)

this gives us,

12a + 15b = 6
-12a - 16b = -6.32

we can now add the two equations together to eliminate the (a), doing so leaves us with

-b = -0.32

divide both sides by -1, to get

b = $0.32

We can now plug (b) into equation 1 or 2, to get (a)

I will go with (1)

4a + 5(0.32) = 2
4a + 1.6 = 2

subtract 1,6 from both sides

4a = 0.4

divide both sides by 4

a = $0.1

Answer 5

The cost for pencil = $0.1.
The cost for pen = $0.32