Question

Solve the equation 1+4+7+⋯+x=925

Answer 1

Answer:

Now, :

∴ Value of

Step-by-step explanation:

73 is the answer pakka

Answer 2

Solution:

here , the equation is 1+4+7+....+x = 925

for testing it is in A.P or not

4-1 =3 = 7-4   so, it is ne A.P

let, a be the first term of the A.P

d be the common difference of the A.P

n ne the no. of term of the A.P

S be the sum of the A.P

given, a =1

          d = 3

          S = 925

now, S= n/2[2a+(n-1)d]

      925 = n/2[ 2*1+(n-1)*3]

       3n^2 -n -1850 =0

n= (1+- √1+4*3*1850)/2*3

n= (1+- √22201)/6

n= (1+-149)/6

n=(1+149)/6    or n= (1-149)/6      

n= 150/6          or n= 148/6

n= 26               or n= 24.666 , which is not possible

so, n= 26

since x is 26th term

x =a+ (n-1)d

x =1 +(26-1)*3

x= 76