Solve the equation :
1 + 5 + 9 + 13 +...... +x = 1326
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x = 101
Step-by-step explanation:
series is in AP
Sum of AP is
S = N/2(2a + (N-1)d)
1326= N/2(2 + 4N - 4)
2652= 4N^2 - 2N
it becomes quadratic in N
4N^2 - 2N -2652= 0
4N^2 - 104N + 102N -2652=0
4N( N- 26) +102(N-26) =0
from the above we will get N= 26
last term will be (a +25d)= 101
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