Question

daca x supra y = 3 supra 4 calculati a)x supra x + y b) 3x-y supra 2x

dau 95 de puncte si coronița
urgent !!!​

Answer 1

Răspuns:

x/y=3/4=>x/3=y/4=k

x=3k

y=4k

3k/(3k+4k)=3k/7k=3/7

__________

(3x-y)/2x=(9k-4k)/6k=5k/6k=5/6

Answer 2

Răspuns:

Explicație pas cu pas:

x/y = 3/4 ⇒  4 x = 3 y → produsul mezilor = produsul extremilor

x/3 = y/4 = k → coeficient de proportionalitate

x/3 = k ⇒  x = 3 k

y/4 = k ⇒  y = 4 k

a)

x/(x+y) = 3k/(3k+4k) = 3k/7k = 3/7

___________________________

b)

(3x-y)/2x =

= (3×3k-4k)/(2×3k) =

= (9k-4k)/6k =

= 5k/6k = → simplific k/k=1

= 5/6