Asked by Isaac
If the third term of a linear sequence is 20 and the sum of the first ten terms 275. Find the first term and the common difference
Answers
Answered by
oobleck
a+2d = 20
10/2 (2a+19d) = 275
or, to make things easier,
a + 2d = 20
10a + 95d = 275
Now solve for a and d as usual
10/2 (2a+19d) = 275
or, to make things easier,
a + 2d = 20
10a + 95d = 275
Now solve for a and d as usual