by ice_breaker » Tue Feb 23, 2010 12:34 pm
Thank you Teacher.
I did have a look at your given site and some sites thru Google. Finally, I figure out the solution as below:
3 + 3^2 + 3^3 + 3^4 + 3^5 + 3^6 + 3^7 + 3^8 + 3^9 + 3^10
1) Get out a common factor
3(1 + 3^2 + 3^3 + 3^4 + 3^5 + 3^6 + 3^7 + 3^9)
2) Use the formula [(a^n - b^n)/2] , as a=3, b=1, to calculate the parenthesis, then multiply by 3
3 * [(3^10 - 1^10)/2] = 88 572.
The result is 88,572.
Is this correct Teacher? Please advise
Thank you Teacher.
I did have a look at your given site and some sites thru Google. Finally, I figure out the solution as below:
3 + 3^2 + 3^3 + 3^4 + 3^5 + 3^6 + 3^7 + 3^8 + 3^9 + 3^10
1) Get out a common factor
3(1 + 3^2 + 3^3 + 3^4 + 3^5 + 3^6 + 3^7 + 3^9)
2) Use the formula [(a^n - b^n)/2] , as a=3, b=1, to calculate the parenthesis, then multiply by 3
3 * [(3^10 - 1^10)/2] = 88 572.
The result is [b]88,572[/b].
Is this correct Teacher? Please advise