Determine the 2nd and kth term of an AP whose 9th term is -2.6 and 23rd a
is -5.4
Answers
Step-by-step explanation:
9th term = a+(n-1)d
=>> a+(9-1)d=-2.6
=>> a+8d=-2.6 ------(1)
23rd term = a+(n-1)d
=>> a+(23-1)d = -5.4
=>> a+22d=-5.4 -----(2)
(2)-(1)
= a+22d=-5.4
a+8d = -2.6
___________
14d =-2.8
=>> d= -0.2
Substituting d=-0.2 in (1)
a+8(-0.2) = -2.6
a-1.6=-2.6
a=-2.6+1.6
a=-1
2nd term = a+(n-1)d = a+(2-1)d
=>> a+d = -1+-0.2 = -1.2
Kth term = a+(n-1)d = a+(k-1)d
=>> -1 + (k-1)-0.2
=>> -1 -0.2k+0.2
=>> -0.8-0.2k
=>> -0.2(4+k)
Hope it will help you...
Step-by-step explanation:
9th term = a+(n-1)d
=>> a+(9-1)d=-2.6
=>> a+8d=-2.6 ------(1)
23rd term = a+(n-1)d
=>> a+(23-1)d = -5.4
=>> a+22d=-5.4 -----(2)
(2)-(1)
= a+22d=-5.4
a+8d = -2.6
___________
14d =-2.8
=>> d= -0.2
Substituting d=-0.2 in (1)
a+8(-0.2) = -2.6
a-1.6=-2.6
a=-2.6+1.6
a=-1
2nd term = a+(n-1)d = a+(2-1)d
=>> a+d = -1+-0.2 = -1.2
Kth term = a+(n-1)d = a+(k-1)d
=>> -1 + (k-1)-0.2
=>> -1 -0.2k+0.2
=>> -0.8-0.2k
=>> -0.2(4+k)