Question

1)

a+b=100 a/b=2/3 P.S / înseamnă fractie


2)

x/y =3/4

Aflati 2x+5y/5y

Answer 1

a)a/b=2/3 rezulta a/2=b/3 si a=2n, b=3n
Inlocuim 2n+3n=100
5n=100
n=20
a=40
b=60
b)x=3n, y=4n
2*3n+5*4n/5*4n=6n+20n/20n=26n/20n=26/20=1,3

Answer 2

1)
a+b=100
a/b=2/3
a=2b/3
2b/3+b=100
2b+3b=100x3
5b=300
b=300:5
b=60
a+60=100
a=100-60
a=40

2)
x/y=3/4
4x=3y
2x=3y/2
(3y/2+5y)/5y=[(3y+10y)/2] / 5y=13y/10y=13/10