Răspuns:
Explicație pas cu pas:
3v+2y supra 2x+5y stiind ca x supra y =4 supra 7.
x/y = 4/7
x = 4y/7
3x + 2y = 12y/7 + 2y = 12y/7 + 14y/7 = 26y/7
2x + 5y = 8y/7 + 5y = 8y/7 + 35y/7 = 43y/7
fractia devine 26y/7 : 43y/y = 26/43
____________________
2x+5y supra 7x-y stiind ca x supra y = 12 supra 5
x/y = 12/5
x = 12y/5
2x + 5y = 24y/5 + 25y/5 = 49y/5
7x - y = 84y/5 - 5y/5 = 79y/5
fractia devine 49y/5 : 79y/5 = 49/79