a.
(59,25-3,25 . 6,5): 625%
= (59,25-21,125): 625%
=38,125: 625%
= 0,16
b.
45.16−$\frac{17}{15}$ .15+28
= 45.(15+1)−$\frac{17}{15}$.15+28
= 45.15+45−$\frac{17}{15}$.15+28
= 45.15+$\frac{28}{45}$ .15+28
= $\frac{28}{28}$
= 1
c.
65 . 20,04+8 . 20,04+20,04 . 2923+2004 . 20,4
= 20,04.( 65+8+2923)+2004 . 20,4
= 20,04.2996+2004 . 20,4
= 60039,84+40881,6
= 100921,44