3 packs of pencils ( 30 pencils)
5 packs of erasers (30 erasers)

The equation of a elipse:

The length of the major axis is equal 2a if a > b or 2b if b > a.
We have

therefore the length of the major axis is equal 2 · 7 = 14.
Exponent way n
exponetional way
Answer:
Step-by-step explanation:
First one is 19. The work is 7+7+5=19
Second one is 22. The work is 12+5+5=22
Third one is 15. The work is 3+3+3+3+3=15