Question

the houses in a row are numbered consequently from 1 to 49 show that the sum of the numbers of the houses preceding the house number x is equal to the sum of the numbers of the house following x ​

Answer 1

answers :

the houses in a row are numbered consecutively from 1 to 49

and these numbers are in AP

d =1

a =1

a^n =49

according to the question:

s(x-1 )= s(49) -sx

s (x-1 )+sx=s49

(x-1)/2 +(1+x-x)+x/2*(1+x)=49/2 *50

x(x-1 ) +x(x+1) =49*50

x(x-1+1)=49*50

x(x-1+x+1)=49*50

2x^2=49*50

×^2 =49*25

×=35