2x 3y = 7
(k + 1) x + (1 2k) y = 5k 4
Sol .
Q. 19. The 5th and 15th term of an A.P. are 13 and – 17 respectively. Find the sum of first 21 terms of the A.P. Sol. Let a and d be the 1st term and common difference respectively.
| Mathematics 2008 Question Papers Class X | |||||||
| Delhi | Outside Delhi | Compartment Delhi | Compartment Outside Delhi | ||||
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Set 2 | ||||
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Set 3 | |
Set 3 | ||||
