Question

the 4th term of an ap is 11. and the sum of 5th and 7th term is 24. find d ​

Answer 1

Answer:

d=1/2

Step-by-step explanation:

nth term=a+(n-1)d

4th term=a+3d=11

5th term+11th term=(a+4d)+(a+6d)=24

=2a+10d=24

÷by2=a+5d=12

(a+5d=12)-(a+3d=11)gives2d=1

then d=1/2

Answer 2

SOLUTION

Let a be the first term & d be the common difference.

Now,

a4= 11

=) a+3d= 11.......(1)

Also,

a5+ a7= 24

=) a+4d+ a+6d= 24

=) 2a+ 10d= 24

=) a+ 5d= 12.......(2)

Subtracting (1) from (2), we get

=) 5d-3d= 12-11

=) 2d= 1

=) d= 1/2

Hope it helps ☺️❤️