Răspuns :
[tex]a+b= 45kl \\ a=4b \\ 4b+b=45 \\ 5b=45 \\ b=45:5 \\ b=9 kl intr-o cisterna \\ a=4*9=36 kl in a2a cisterna[/tex]
a+b=45kl=45000l;
⇒a=4b
⇒4b+b=45000l
⇒5b=45000l
⇒b=9000l[de ulei-a doua cisterna];
⇒a=4·9000l
⇒a=36000l[de ulei-prima cisterna];
⇒a=4b
⇒4b+b=45000l
⇒5b=45000l
⇒b=9000l[de ulei-a doua cisterna];
⇒a=4·9000l
⇒a=36000l[de ulei-prima cisterna];