[latex]a)\...=frac{4}{10}+0,7=0,4+0,7=1,1\\...=4,5+frac{3cdot125}{8cdot125}=4,5+frac{375}{1000}=4,5+0,375=4,875\\...=7frac{6}{10}-0,8=7,6-0,8=6,8\\...=10,25-3frac{25}{4cdot25}=10,25-3frac{25}{100}=10,25-3,25=7[/latex] [latex]b)\...=4frac{2}{10}+12,05=4,2+12,05=16,25\\...=64,5-18frac{125}{8cdot125}=64,5-18frac{125}{1000}=64,500-18,125=46,375\\...=33,65-12frac{3cdot25}{4cdot25}=33,65-12frac{75}{100}=33,65-12,75=20,9\\...=28,8-14frac{5}{10}=28,8-14,5=14,3[/latex] [latex]c)\...=frac{5}{10}cdot2,3=0,5cdot2,3=1,15\\...=0,9cdotfrac{3cdot25}{4cdot25}=0,9cdotfrac{75}{100}=0,9cdot0,75=0,675\\...=1,5:2frac{5}{10}=1,5:2,5=15:25=3:5=frac{3}{5}=0,6\\...=5,1:4frac{25}{4cdot25}=5,1:4frac{25}{100}=5,1:4,25=510:425=102:85\\=1frac{17}{85}=1frac{1}{5}[/latex]
