Siince 2nd equation is already equal a, subsitute b-2 for a in the other equation
b-2-3b=28
-2-2b=28
add 2 to both sides
-2b=30
divide both sides by -2
b=-15
sub back
a=b-2
a=-15-2
a=-17
(a,b)
(-17,-15)
3rd choice
a. First five terms: 9,13,17,21,25
b. Sum of first 25 terms = 1425
c. The given sequence is an arithmetic sequence because the common difference between two consecutive terms is same.
Further explanation:
Given
Formula of sequence

<u>1. First 5 terms:</u>
For first 5 terms, we have to put n=1,2,...5,
So,

<u>2. Sum of first 25 terms:</u>
For that we have to find 25th term first

The formula for sum is:

<u>3. Type of sequence</u>
The given sequence is an arithmetic sequence because the common difference between two consecutive terms is same.
i.e.

Keywords: Arithmetic sequence, Sum of arithmetic sequence
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I think the answer might be 72
Hi , the answer is 15 miles per hour because 45 divided by 3 equals 15 , one hour equals to 15 , two hours =30 and three hours =45 , it goes by 15.
1+1 = 2 that is the answer