5th term of an arithmetic sequence is 17 and its 10th term is 32 .
a) What is its common difference ?
b) What is its first term ?
c) Find the position of 92 in this sequence ?
Answers
Answered by
1
Answer:
a) d=3
b) a=5
c) 278
Step-by-step explanation:
a5 = a + 4d = 17------ (1)
a10 = a + 9d = 32------(2)
solving 1 and 2 ,
d=3
a=5
a92 = a+91d= 5+91*3=278
Answered by
1
Answer:
(a)Common difference(d)=3
(b) First term (a)=5
(c) Position of 92 =30
Step-by-step explanation:
(A)
a5=17
a+4d =17..........let 1st equation
a10 =32
a+9d =32..........let 2nd equation
solve 1st equation
a+4d =17
a=17 - 4d(put this value in 2nd equation)
a+9d =32
(17 -4d) +9d=32
17 -4d+9d =32
17+5d=32
5d =32-17
5d =15
d=15/5
d=3
(B)
d=3 (put this value in 1st equation )
a+4d=17
a+4(3)=17
a+12=17
a=17-12
a=5
(C)
an=a+(n-1)d
92=5+(n-1)3
92-5=3n-3
87=3n-3
87+3=3n
90=3n
90/3=n
30=n
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