Вычисли рациональным способом (2/3+3/4+4/5)+(1/6+2/7+3/8)+(5/8+5/7+5/6)+(1/5+1/4+1/3)

Question

Вычисли рациональным способом (2/3+3/4+4/5)+(1/6+2/7+3/8)+(5/8+5/7+5/6)+(1/5+1/4+1/3)

Answer 1

 (2/3+3/4+4/5) + (1/6+2/7+3/8) + (5/8+5/7+5/6) + (1/5+1/4+1/3) = 
= [ (2/3+3/4+4/5) + (1/5+1/4+1/3) ] + [ (1/6+2/7+3/8) + (5/8+5/7+5/6) ] =
= (2/3 + 1/3) + (3/4 + 1/4) + (4/5 + 1/5) + (1/6 + 5/6) + (2/7 + 5/7) + (3/8 + 5/8) = = 3/3 + 4/4 + 5/5 + 6/6 + 7/7 + 8/8 = 1 + 1 + 1 + 1 + 1 + 1 = 6