Answer:
300 cents or $3
Step-by-step explanation:
Let p be the cost of one pen and m be the cost of one mechanical pencil. We can use this to set up a system of equations:
4p+6m=1620 (convert $16.20 to cents by multiplying it by 100)
m=70
We can solve this using substitution (substitute 70 for m):
4p+6(70)=1620
4p+420=1620
Subtract 420 from both sides
4p=1200
Divide both sides by 4
p=300 cents or $3
