Find the APs in the following missing terms in the boxes :4,11,_,25
Answers
Answered by
0
Step-by-step explanation:
For this A.P.,
a=2
a
3
=26
We know that, a
n
=a+(n−1)d
a
3
=2+(3−1)d
26=2+2d
24=2d
d=12
a
2
=2+(2−1)12
=14
Therefore, 14 is the missing term.
(ii) For this A.P.,
a
2
=13 and
a
4
=3
We know that, a
n
=a+(n−1)d
a
2
=a+(2−1)d
13=a+d ... (i)
a
4
=a+(4−1)d
3=a+3d... (ii)
On subtracting (i) from (ii), we get,
−10=2d
d=−5
From equation (i), we get,
13=a+(−5)
a=18
a
3
=18+(3−1)(−5)
=18+2(−5)=18−10=8
Therefore, the missing terms are 18 and 8 respectively.
(iii) For this A.P.,
a
1
=5 and
a
4
=9
2
1
We know that, a
n
=a+(n−1)d
a
4
=5+(4−1)d
9
2
1
=5+3d
d=
2
3
a
2
=a+d
a
2
=5+
2
3
a
2
=
2
13
a
3
=a
2
+
2
3
a
3
=8
Answered by
1
Answer:
18
Step-by-step explanation:
given :
a=1
d= 11-4= 7
n= 3
= a +(n-1) d
= 4+(3-1) x 7
= 4+2 x7
= 4+14
= 18
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