Problema 7, vă rog!

Răspuns:
x/y=5
a)(x+y)/y=y/y(x/y+1)=5+1=6
b)(2x+y)/2y=y/2y(2x/y+1)=
1/2(10+1)=11/2
c)(5x-3y)4y=y4y(5xy-3)=
1/4(25-3)=22/4=11/2
d)(4x-y)/3y=y/3y(4x/y-1)=1/3(20-1)=19/3
Explicație pas cu pas: