the 9th term of an ap is -32 and the sum of its 11th and 13th term is -94 find AP
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term9 = a + 8d = -32 ____eq. 1
term11 + term13 = -94
(a + 10d) + (a + 12d) = -94
2a +22d = -94
a + 11d = -47 _____eq. 2
Now solving it simultaneously,
we get
a+8d = -32
a+11d=-47
-_________
-3d= 15
d=-5
Putting the value of d,
-32 = a + 8*-5
-32=a - 40
a = 8
Therefore, the AP is 8 , 3, -2..........
term11 + term13 = -94
(a + 10d) + (a + 12d) = -94
2a +22d = -94
a + 11d = -47 _____eq. 2
Now solving it simultaneously,
we get
a+8d = -32
a+11d=-47
-_________
-3d= 15
d=-5
Putting the value of d,
-32 = a + 8*-5
-32=a - 40
a = 8
Therefore, the AP is 8 , 3, -2..........
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