Question

for an ap T3 equals to 8 and T4 equals to 12 find the common difference d

Answer 1

T3= 8
T4= 12
D= T4-T3
= 12-8
=4

Answer 2

t3=t+(3-1)d
8=t+2d-------(1)
t4=t+(4-1)d
12=t+3d------(2)
from eq 1 &2 sub(-)
(t+2d=8)-(t+3d=12)
-d=-4
d=4
:-)
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