The cost of 3 notebooks and 2 pencils is $5.10. At the same prices, the cost of 2 notebooks and 3 pencils is $4.65. What is the total cost of a 1 notebook and 1 pencil ?

Answer:
$1.95
Step-by-step explanation:
notebook = n
pencil = p
3n + 2p = 5.10
2n + 3p = 4.65
multiply top equation by 2 and bottom by 3
6n + 4p = 10.20
6n +9p = 13.95
subtract bottom equation from the top equation
-5p = -3.75
divide by 5, negatives cancel out
p = 0.75
sub p into either equation, I chose the original top equation
3n + 2(0.75) = 5.10
3n + 1.50 = 5.10
subtract 1.50 from both sides
3n = 3.60
divide both sides by 3
n = 1.20
p = 0.75
n + p = 1.95 (the fourth option)