Question

solve the sum 15,19,20,21,22 plz​

Answer 1

Answer:

Hello Mate........

15 , 19 , 20 , 21 , 22

For this series :

First term, a = 15

It can be Observed that ,

a1 - a2 = 19 - 15 = 4

a3 - a2 = 20 - 19 = 1

Since, difference between these terms is not same.

Therefore, the above series is not an A. P

Hope it Helps u !

Thanks :)

Answer 2

Step-by-step explanation:

15.) 1-225a^2

= 1^2 - (15a)^2

=(1+15) (1-15) Answer

19.) (403)^2 - (397)^2

= (403+397) (403-397) Answer

20.) (0.8)^2 -(0.2)^2

=(0.8+0.2) (0.8-0.2) Answer

21.) (1.4)^2 - (0.6)^2

=(1.4+0.6) (1.4-0.6) Answer

22.) (173)^2 - (127)^2

= (173+127) (173-127) Answer