2/35+23/25+1/49+13/49=((2/35+23/35)+1/49)+13/49
2+23 supra 35=5/7
(5/7+1/9)+13/49=5*7+1 supra 49=36/49
36/49+13/49=36+13 supra 49=49/49=1/1=1
7/30+11/10+2/17+11/51=((7/30+11/10)+2/7)+11/51
7/30+11/10=7+11*3 supra 30=4/3
(4/3+2/17)+11/51=4*17+2*3 supra 51=68+6 supra 51=74/51
74/51+11/51=74+11 supra 51=85/51=5/3=1.66667