Jim paid $ 5.55 for 1 notepad and 7 pencils. Anne paid $ 12.28 for 3 notepads and 2 pencils. How much does each notepad cost? Show all work

2 answers

1n + 7p = 5.55
3n + 2p = 12.28

from the first:
n = 5.55-7p

sub into the 2nd

3(5.55-7p) + 2p = 12.28
16.65 - 21p + 2p = 12.28
-19p = -4.37
p = .23

then n = 5.55 - 7(.23) = 3.94

check:
1 notebook + 7 pencils
= 3.94 + 7(.23) = 5.55
3 notebooks + 2 pencils
= 3(3.94) + 2(.23) = 12.28

checks out!
1n+7p = 5.55
3n+2p = 12.28

that's the same as

2n+14p = 11.10
21n+14p = 85.96

now subtract to get rid of the p's

19n = 74.86
n = 3.94