Răspuns :

Explicație pas cu pas:

7l×a=42l

a=42l:7l

a=6l

v:7l×6l=42l

93l+a=100l

a=100l-93l

a=7l

V:93l+7l=100l

425ml-a=137ml

a=425ml-137ml

a=288ml

v:425ml-288ml=137ml

a-75ml=125ml

a=125ml+75ml

a=200ml

v:200ml-75ml=125ml