Math, asked by yashas23, 1 year ago

Sn=75000 a=1500 d=500 find n​

Answers

Answered by sana6978
2

Step-by-step explanation:

Sn=75000

a=1500

d=500

to find n

required formula Sn=n/2[2a+(n-1)d]

75000=n/2[2(1500)+(n-1)500]

75000×2=n[3000+500n-500]

150000=n[500n+2500]

500n²+2500n-150000=0

n²+5n-300=0

n²+20n-15n-300=0

n(n+5)-15(n+5)=0

n-15=0,n+5=0

n=15,n=-5

n=15,-5

Similar questions