Question

Rezolvare completa va rog! ​

Answer 1

Răspuns:

Explicație pas cu pas:

x/y=5/7=> x=5y/7

a) (y-x)/2x=

y-x= y-5y/7= 7y/7-5y/7=2y/7

(y-x)/2x=2y/7/ 2 ori 5y/7= 2y/7/10y/7= 2y/7 : 10y/7= 2y/7 ori 7/10y= 2y/10y= 1/5

b) x/(y-x)

y-x= y- 5y/7= 7y/7-5y/7=2y/7

x/ (y-x)= 5y/7/ 2y/7= 5y/7 :2y/7= 5y/7 ori 7/2y= 5y/2y= 5/2

c) 2x/ (x+y)

x+y= 5y/7+y= 5y/7+7y/7=12y/7

2x / (x+y)= 2 ori 5y/7/ 12y/7= 10y/7/12y/7= 10y/7 : 12y/7= 10y/7 ori 7/12y= 10y/12y= 10/12= 5/6

d) 2y / (x+y)

x+y= 12y/7

2y/ (x+y)= 2y/ 12y/7= 2y: 12y/7= 2y ori 7/12y= 14y/12 y se simplifica cu y= 14/12 se simplifica cu 2= 7/6

exercitiul 14

3x/2y= 1,25=> x=( 2y ori 1,25)/3= 2,5y/3

a) (2x+y)/y=

2x+y= 2ori 2,5y/3+y= 5y/3+y= 5y/3+3y/3= 8y/3

(2x+y)/y= 8y/3/y=8y/3:y= 8y/3 ori 1/y= 8/3

b) (2x-y)/x

2x-y= 2 ori 2,5y/3- y= 5y/3-y= 5y/3- 3y/3= 2y/3

(2x-y)/x= 2y/3/2,5y/3=2y/3:2,5y/3= 2y/3 ori 3/2,5y= 2y/2,5y se simpligfica y= 2/2,5= 2/25/20= 2:25/10= 2 oei 10/25= 20/25 se simplifica cu 5= 4/5

c) (4x-3y)/5y=

4x-3y= 4 ori 2,5y/3 -3y= 10y/3- 3y= 10y/3- 9y/3= y/3

(4x-3y)/5y= y/3/5y= y/3 :5y= y/3 ori 1/5y= y/15y se simplifica y= 1/15