Answer:
It actually depends on where the point of letter is
Answer: 
Step-by-step explanation:
Move all terms to one side
Simplify
Split the second term
Factor out common terms in the first two terms, then in the last two terms.
Factor out the common term

Answer:
21.70
Step-by-step explanation:
First find the discount
31 * 30%
31 *.30
9.3
Subtract from the original amount
31 - 9.3
21.70
Answer:
Step-by-step explanation:
9x - 4 + 5x + 16 = 180
14x + 12 = 180
14x = 168
x = 12
1)t=S/U=2.4/12=0.2
2)t=S/U=8.4/36=0,23
3)0.23-0.2=0.03