Răspuns:
3. [tex]\frac{t}{3} +50=\frac{3t}{4}[/tex] aducem la acelasi numitor t=total pasageri
[tex]\frac{9t-4t}{12}[/tex]=50 5t= 12*50 5t=600 t= 600:5 =120 pasageri
total pasageri 120
120*3 :4= 90 locuri ocupate
5. a= 2b+1 ( a =nr de elevi, b= nr de banci)
a=3*(b-4)
2b+1=3b-12 3b-2b= 1+12 b=13 banci
a=13*2+1= 26+1=27 elevi
