1) 1/2 +1/4 =(2+1)/4 =3/4 =0.75
2) 3/2 +1/4 =(6+1)/4 =7/4 =1.75
3) 3/4 -1/2 =(3 -2)/4 =1/4 =0.25
4) 1/3 +1/9 =(3+1)/9 =4/9
5) 2/3 +1/9 =(6 +1)/9 =7/9
6) 2/3 -1/9 =(6 -1)/9 =5/9
7) 1/2 +3/4 =(2+3)/4 =5/4 =1.25
8) 1/2 -1/4 =(2 -1)/4 =1/4 =0.25
9) 3/2 -1/3 =(3*3 -2)/6 =(9 -2)/6 =7/6 =1 1/6(одна целая одна шестая)