he sum of the 3rd and 7th terms
of
an
A.P.
is 32 and
their product
is 220. Find take a value
d positve
Answers
Answered by
1
Answer:
A.P.=4,7,10,.. or 4,1,-2,... or 28,31,34,... or 28,25,22,...
Step-by-step explanation:
t3+t7=32
a+2d+a+6d=32
2a+8d=32
a+4d=16
a=16-4d
(a+2d)(a+6d)=220
a²+8ad+12d²=220
(16-4d)²+8(16-4d)d+12d²=220
256+16d²-128d+128d-32d²+12d²=220
-4d²=-36
d²=9
d=3 or d=-3
a=16-4(3)=16-12=4
a=16-4(-3)=16+12=28
A.P.=4,7,10,.. or 4,1,-2,... or 28,31,34,... or 28,25,22,...
HOPE THIS HELPS!
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