Question
The sum of sixth term of a.p is 72 and the second term is seven times fifth term find the first term,common difference and the sum of tenth term
Answers
Steve
garbled English, but I think you want
6/2 (2a+5d) = 72
a+d = 7(a+64d)
solve that for a and d, and then evaluate
10/2 (2a+9d)
6/2 (2a+5d) = 72
a+d = 7(a+64d)
solve that for a and d, and then evaluate
10/2 (2a+9d)
Shashank
S6=72
6a+15d=72 call as eq 1
T2=7(a+4d)
a+d=7a+28d
6a+27d=0 call as eq 2
Consider the eq 1&2 simultaneously
6a+15d=72 eq 1
6a+27d=0 eq 2
Subtract 1&2
We get
-12d=72
d=-6
evaluate d=-6 in eq 2
We get a=27
To find s10
=10/2(2*27+(10-1)-4)
=5(54-36)
=5(18)
=90
6a+15d=72 call as eq 1
T2=7(a+4d)
a+d=7a+28d
6a+27d=0 call as eq 2
Consider the eq 1&2 simultaneously
6a+15d=72 eq 1
6a+27d=0 eq 2
Subtract 1&2
We get
-12d=72
d=-6
evaluate d=-6 in eq 2
We get a=27
To find s10
=10/2(2*27+(10-1)-4)
=5(54-36)
=5(18)
=90
Edina lucia
Velocity 20m/s find the components of the planes velocity if take off angles is
a) 45° .
B)60°
C) 70°
a) 45° .
B)60°
C) 70°