The sum of first 7 term of a arithmetic sequence is 119 and the sum of first 11 terms is 275.
a) What is it's 4th term?
b) What is it's 6th term?
c) What is it's common deference?
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Taking n as the term, we have a formula for arithmetic sequences: the nth term = an+b.
Therefore for 7th term: 119 = 7a + b
And for 11th term: 275 = 11a + b
Solving these two equations, we get: a = 39, b = (-144)
Therefore, our equation is: nth term = 39n - 144
a) Put n = 4 and solve the equation.
b) Put n = 6 and solve the equation.
c) I am not sure of the answer.
Therefore for 7th term: 119 = 7a + b
And for 11th term: 275 = 11a + b
Solving these two equations, we get: a = 39, b = (-144)
Therefore, our equation is: nth term = 39n - 144
a) Put n = 4 and solve the equation.
b) Put n = 6 and solve the equation.
c) I am not sure of the answer.
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