Question

Calculati :
(1 pe 1*2 + 1 pe 2*3 + ..... + 1 pe 99*100)/[(3pe9)⁴*(3pe5)³/(3pe5)⁵]=

Answer 1

[1/(1·2) + 1/(2·3) +1/(3·4) + ......+1/(99·100)]÷[1/3^4 ·3³/5³ ·5^5/3^5] = [1/1-1/2+1/2-1/3+1/3-1/4+.....+1/99 -1/100]÷5²/3^6=(1/1- 1/100) × 3^6/5² = 99/100 ·3^6/5² = (11·3^8 )/(2²·5^4 )