Question

solve the equation AP 1+4+7+10....+x=287 find X

Answer 1

Step-by-step explanation:

a=1

a2=4

d=a2-a=4-1=3

an=x=a+(n-1)d=1+(n-1)3

x=1+3n-3=3n-2

x+2=3n, n=(x+2)/3

Sn=287

Sn=n/2(a+an)

287=n/2(1+x)

287*2=(x+2)(1+x)/3

287*2*3=x+x²+2+2x

Now, it is a quadratic equation. Just solve this equation for 'x'.