Question

2) Daca:
a)x+y/y=2/3, calculati x/y
b)2x/2x+3y=1/5, calculati x/y
c)x+y/3x-y=2/3,calculati x/y
d)2y-3x/4x+5y=2/11, calculati x/y​

Answer 1

Răspuns:

Explicație pas cu pas:

2) Daca:

a) x+y/y=2/3, calculati x/y

(x+y)/y=2/3  ⇔3(x+y)=2y  ⇔3x=2y-3y  ⇔3x=-y |: (3y)  ⇔3x/3y=-y/3y  ⇔x/y=-1/3

b) 2x/2x+3y=1/5, calculati x/y

2x/(2x+3y)=1/5  ⇔2x+3y=10x  ⇔3y=8x | : (8y)  ⇔3y/8y=8x/8y  ⇔x/y=3/8

c) x+y/3x-y=2/3,calculati x/y

(x+y)/(3x-y)=2/3  ⇔3(x+y)=2(3x-y)  ⇔3x+3y=6x-2y  ⇔5y=3x | : (3y)  ⇔5y/3y=3x/3y  ⇔x/y=5/3

d) 2y-3x/4x+5y=2/11, calculati x/y​

(2y-3x)/(4x+5y)=2/11  ⇔11(2y-3x)=2(4x+5y)  ⇔22y-33x=8x+10y  

⇔12y=41x | : (41y)  ⇔12y/41y=41x/41y  ⇔x/y=12/41