if a6=-10 and a10=-26 in A.P find a15
Answers
Answered by
4
Answer: -46
Step-by-step explanation: first of all let's find the value of "d"
a10-a6 = difference of 4 terms
& a10= -26, a6 =-10
The difference of 4 terms = (-26) - (-10)
Which is -16
So as the difference is 4 terms we shall divide -16 by 4 to get difference of 1 term
Which is -4
So "d" = -4
So now let's find first term "a"
As per formula, tn = a+(n-1) d
t6 = a+(6-1) -4 ( t6 = a6)
-10 = a(5) -4
-10 = a(-20)
a = 10
Now a15 = t15
t15 = a+(n-1) d
t15 = a+(15-1) d
t15 = 10+ (14) -4
t15 = 10 + (-56)
t15 = -46
Similar questions