b) 0,75-5/7=3/4-5/7=21/28-20/28=1/28 c)2 2/3:0,32=8/3:32/100=8/3:8/25=8/3*25/8=25/3=8 1/3 d)2,7×1 1/9=2 7/10*10/9=27/10*10/9=27/9=3

b) 0,75 - [latex] frac{5}{7} [/latex] = [latex] frac{75}{100} [/latex] - [latex] frac{5}{7} [/latex] = [latex] frac{3}{4} [/latex] - [latex] frac{5}{7} [/latex] = [latex] frac{21}{28} [/latex] - [latex] frac{20}{28} [/latex] = [latex] frac{1}{28} [/latex] c) 2[latex] frac{2}{3} [/latex] : 0,32 = [latex] frac{8}{3} [/latex] : [latex] frac{32}{100} [/latex] = [latex] frac{8}{3} [/latex] : [latex] frac{8}{25} [/latex] = [latex] frac{8}{3} [/latex] * [latex] frac{25}{8} [/latex] = [latex] frac{25}{3} [/latex] = 8[latex] frac{1}{3} [/latex] d) 2,7 * 1[latex] frac{1}{9} [/latex] = [latex] frac{27}{10} [/latex] * [latex] frac{10}{9} [/latex] = [latex] frac{27}{9} [/latex] = 3