Question

The cost of 3 markers and 2 pencils is $1.80. The cost of 4 markers and 6 pencils is $2.90. What is the cost of each item? Include appropriate units in your answer. :​

Answer 1

Let M = marker cost
Let P = pencil cost

3 markers and 2 pencils cost 1.80 ==> 3M + 2P = 1.80

4 markers and 6 pencils cost 2.90 ==> 4M + 6P = 2.90

Multiply the first equation by (-3) and add it to the second equation

-9M - 6P = -5.40
4M + 6P = 2.90

-5M = -2.50
M = 0.50

Plug this value for M into the 1st equation and solve for P

3*(0.50) + 2P = 1.80
1.50 + 2P = 1.80
2P = 0.30
P = 0.15

So a marker costs 50 cents and a pencil costs 15 cents