Q. Find the 11th term of the arithmetic sequence x+1,−5x+7,−11x+13,…Answer:
Determine common difference: To find the 11th term of an arithmetic sequence, we need to determine the common difference between consecutive terms and then use the formula for the nth term of an arithmetic sequence, which is an=a1+(n−1)d, where an is the nth term, a1 is the first term, n is the term number, and d is the common difference.
Find common difference: First, let's find the common difference d by subtracting the first term from the second term.d=(−5x+7)−(x+1)=−5x+7−x−1=−6x+6
Verify common difference: Now, let's verify the common difference by subtracting the second term from the third term. d=(−11x+13)−(−5x+7)=−11x+13+5x−7=−6x+6This confirms that the common difference is indeed −6x+6.
Find 11th term: Using the formula for the nth term, we can now find the 11th term a11.a11=a1+(11−1)(−6x+6)=(x+1)+10(−6x+6)
Simplify expression: Simplify the expression to find the 11th term.a11=x+1+10(−6x)+10(6)=x+1−60x+60
Combine like terms: Combine like terms to get the final expression for the 11th term.a11=−59x+61
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