3a=2b⇒a=[tex] \frac{2b}{3} [/tex]
a+b=250
inlocuim in ecuatiei si scriem
[tex] \frac{2b}{3} [/tex]+b=250
amplicam pe b cu 3
[tex] \frac{2b+3b}{3} [/tex]=250
[tex] \frac{5b}{3} =250[/tex]
b=250*3/5
b=150
a=2*150/3
a=100
2. a+b=80
a-b=3b⇒ a=3b+b⇒a=4b
4b+b=80
5b=80
b=16
a=16*4⇒a=64
3.a+b=200
6a=2b ⇒[tex]a= \frac{2b}{6} [/tex]⇒[tex]a= \frac{b}{3} [/tex]( am simplificat)
inlocuim in ecuatie
[tex] \frac{b}{3} [/tex]+b=200
il amplificam pe b cu 3
[tex] \frac{b+3b}{3} =200[/tex]
[tex] \frac{4b}{3} =200[/tex]
b=3*200/4
b=150
a=150/3⇒a=50
