Question

Solve the equation:
1 + 4 + 7 + 10.......+ x = 287​

Answer 1

given in AP

a=1,d=3,sn=287and an=x

sn=n/2(2a+(n-1)d)

287=n/2(2(1)+(n-1)3)

287=n/2(2+(n-1)3)

287=n/2(2+3n-3)

287*2=n(-1+3n)

574=-n+3n^2

574/3=n+n^2

191.33=n+n^2

now.you can easily find no of terms by this

hope this is helpful for you

Answer 2

Answer:

This is an arithmetic progression(AP)

First term(a)=1

Common difference (d)=3

Last term (l)= x

Number of terms=n

Sum of the AP(S)=287

S=[n(a+x)]/2

287=n(1+x)/2

This question has some values missing.

Please mark the answer Brainliest!!