The answer is the first one
Given two points; (x₁,y₁) and (x₂,y₂) the slope is:
m=(y₁-y₂) / (x₁-x₂) or m=(y₂-y₁) / (x₂-x₁)
In this case:
(4,3)
(5,2)
m=(5-4)/(2-3)=1/-1=-1
Answer: the slope is -1
Change the messy words into numerals
3 times a number minus 2 equals 13
3 × n - 2 = 13
3n - 2 = 13
take 2 to the other side
3n - 2 + (2) = 13 + (2)
3n = 15
Divide by 3 on either sides to isolate n

=

3 and 3 cancels out
n = 5
check:
3 times 5 minus 2 equals 13
3 × 5 - 2 = 13
15 - 2 = 13
13 = 13
The number is 5