Вычислите значение выражения. 1) (1/10*11) + (1/11*12) + (1/12*13) + ...+ (1/49*50) = 1/10 - 1/11 + 1/11 - 1/12 + ...+

1) (1/10*11) + (1/11*12) + (1/12*13) + ...+ (1/49*50) = 1/10 - 1/11 + 1/11 - 1/12 + ...+ 1/49 - 1/50 = 1/10 - 1/50 = 5/50 - 1/50 = 2/25.

2) (3/2*5) + (3/5*8) + (3/8*11) + ... + (3/32*35) = 1/2 - 1/5 + 1/5 - 1/8 + 1/8 - 1/11 + ... + 1/32 - 1/35 = 1/2 - 1/35 = 35/70 - 2/70 = 33/70.