In an arithmetic sequence, the first term, a1, is equal to 9 , and the fourth term, a4, is equal to 39 . Which number represents the common difference of the arithmetic sequence?d=9d=10d=11d=12
Q. In an arithmetic sequence, the first term, a1, is equal to 9 , and the fourth term, a4, is equal to 39 . Which number represents the common difference of the arithmetic sequence?d=9d=10d=11d=12
Given terms: We are given the first term of the arithmetic sequence, a1=9, and the fourth term, a4=39. To find the common difference, d, we can use the formula for the nth term of an arithmetic sequence, which is an=a1+(n−1)d.
Set up equation: We can set up the equation for the fourth term using the formula: a4=a1+(4−1)d.
Substitute values: Substitute the given values into the equation: $\(39\) = \(9\) + (\(4\) - \(1\))d.
Simplify equation: Simplify the equation: \(39 = 9 + 3d\).
Isolate term with \(d\): Subtract \(9\) from both sides to isolate the term with \(d\): \(39 - 9 = 3d\).
Perform subtraction: Perform the subtraction: \(30 = 3d\).
Divide to solve for d: Divide both sides by \(3\) to solve for d: \(d = \frac{30}{3}\).
Final result: Perform the division: \(d = 10\).
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