a) x/y = 7/5 => x=y×7/5
x-y=24=>7y/5 - y =24
(amplificăm y si 24 cu 5 )
=>7y/5-5y/5=120/5
=> 7y-5y=120 => 2y=120 => y=120:2=>y=60
x=60+y=>x=60+12=>x=72
b)x+y=36 => 7y/5 +y=36
(amplificăm y si 36 cu 5)
=> 7y/5+5y/5=180/5=>7y+5y=180=>12y=180=>y=180:12=>y=15
x=36-y=>x=36-15 =>x=21
c)2x+3y=58=>2×(7y/5)+3y=58 =>
14y/5+3y=58
(amplificăm 3y si 58 cu 5)
=> 14y/5 +15y/5=290/5
=> 14y+15y=290=>29y=290=>y=290:29=>y=10
x=7y/5=>x=7×10/5=>x=7×10/5=>x=70/5=>x= 14
