A) (x+y)/(2x+y)=4/5 5(x+y)=4(2x+y)
5x+5y=8x+4y
5x-8x=4y-5y
-3x=-y inmultim -1
3x=y
x=y/3
x/y=1/3
b) (3x+4y)/(2x+y)=7/3
3(3x+4y)=7(2x+y)
9x+12y=14x+7y
9x-14x=7y-12y
-5x=-5y inmultim -1
5x=5y :5
x=y
x/y=1
c) (6x+4y)/(5x+2y)=3/2
2(6x+4y)=3(5x+2y)
12x+8y=15x+6y
12x-15x=6y-8y
-3x=-2y inmultim-1
3x=2y
x=2y/3
x/y=2/3
d) (5x-4y)/(2x-y)=7/3
3(5x-4y)=7(2x-y)
15x-12y=14x-7y
15x-14x=12y-7y
x=5y
x/y=5