Answer:
Step-by-step explanation:
common difference d=3-1=2
first term a=1
an=a+(n-1)d
2n-1=1+(l-1)2
2n-1=1+2l-2
2n-1=2l-1
l=n
(i used l for number of terms)
number of terms=n

Answer:
it might be 3 one according to me
One fifth of a number n is equal -7 as an equation would look like this:
1/5 n = -7 / * 5 (both sides)
n = -35
So if number n equals -35, then it's true that 1/5n equals -7.
Answer
Sorry, I need points to ask more question.