Answer:
$0.84
Step-by-step explanation:
1. find total cost of both the pen and paper
2. find the amount Sally spent
3. find cost of ruler
The same line is written in two different forms
Answer:
82 units
Step-by-step explanation:
7 x 3 = 21
21 x 2 = 42
7 x 2 = 14
14 x 2 = 28
2 x 3 = 6
6 x 2 = 12
42 + 28 + 12 = 82
From cosine law
c^2 = a^2 + b^2 -2abcos(C)
cos(C) = (a^2 + b^2 - c^2)/2ab
this formula will solve your problem