Răspunsuri

2014-08-07T17:09:23+03:00
A)x= 40/100 *y= 10/25 *y= 2/5*y

x= 2y/5

x/y= 2y/5/y= 2y/5 * 1/y= 2/5

b)(3x+y)/(x+y)=  (3*2y/5 +y)/(2y/5 +y)=

=(6y/5 +y)/ (2y/5 +y)=

= (6y+5y)/5 / (2y+5y)/5=

= 11y/5 /7y/5=

= 11y/5 * 5/7y=  11/7

c)p% din x=y

p/100 * 2y/5=y

p/50 * y/5=y

p/50= y/y/5

p/50= y * 5/y

p/50=5

p=5*50=250%
ce am pus din greseala?
semnul acela de mai sus
/?
/7
este supra sapte