Which one is a rule for the nth term of an arithmetic sequence with a8 = 56 and d = 5?
an=a1+(n-1)*d
a8=a1+(8-1)*5
a8=a1+7*5
a8=a1+35
a8-35=a1
a1=a8-35
a1=56-35
a1=21
So this arithmetic sequence is:
21,26,31,36,41,46,51,56
where did u get 56?
The rule for the nth term of an arithmetic sequence can be represented as:
an = a1 + (n - 1)d
Here, an refers to the nth term of the sequence, a1 represents the first term of the sequence, n represents the position of the term, and d represents the common difference between consecutive terms.
Given that a8 = 56 and d = 5, we can substitute these values into the formula and solve for a1.
a8 = a1 + (8 - 1)5
Simplifying the equation, we have:
56 = a1 + 35
Subtracting 35 from both sides, we get:
a1 = 56 - 35
a1 = 21
Hence, the rule for the nth term of the arithmetic sequence is:
an = 21 + (n - 1)5