Question

sum of consecutive odd number between 1 to 15​

Answer 1

(.5(1+29))²

I realize that you are probably looking at this short expression, and are thinking that this is not a sum, but the result is the same and it is much more compact. It's also much easier to solve. In fact I will show you. So:

1+3= 4

4+5= 9

9+7= 16

16+9= 25

25+11= 36

36+13 =49

49+15= 64

64+17= 81

81+19= 100

100+21= 121

121+23= 144

144+25= 169

169+27= 196

196+29= 225

Or you could arrive at the same answer in the way that I suggested instead.

1+29=30

30÷2=15

15×15=225

Answer 2

Step-by-step explanation:

sum of consecutive no is=n(n+1)/2

=15×(15+1)/2

15×16÷2

120