$\text{a)}$

$4,72+5,28=10$

$6,27+0,97=7,24$

$18,3+3,81=22,11$

 

$\text{b)}$

$14,3-3,14=11,16$

$0,925-0,84=0,085$

$2,33-0,567=1,763$

 

$\text{c)}$

$44-4,4+0,44=39,6+0,44=40,04$

$7,6+0,76+1,74=8,36+1,74=10,1$

$6,4-5,48+7,03=0,92+7,03=7,95$