Răspuns:
ᵇ⁾3/a+ᵃ⁾4/b=ᵃᵇ⁾5 => 3b+4a=5ab
ᵇ⁾(a+3)/a+ᵃ⁾(5b+4)/b=[b(a+3)+a(5b+4)]/ab=
(ab+3b+5ab+4a)/ab=
(6ab+3b+4a)/ab=
(6ab+5ab)/ab=11ab/ab=11
____________________
2a/a+1/a +3b/b+2/b=8
2+1/a+3+2/b=8
5+1/a+2/b=8
1/a+2/b=8-5
1/a+2/b=3
_________________
x/65=4/10
10x=4·65
x=260:10=>x=26
__________
(x+6)/(x+3)=20/14
14(x+6)=20(x+3)
14x+84=20x+60
84-60=20x-14x
24=6x=>x=24:6=>x=4
