1)x/2=y/9=k
x=2k
y=9k
(10x-2y)/(5x+y)= (10*2k -2*9k)/(5*2k +9k)=
=(20k-18k)/(10k+9k)= 2k/19k= 2/19
3)3(3x+4y)=7(2x+y)
9x+12y=14x +7y
9x-14x= 7y-12y
-5x= -5y
5x=5y
x=y
x/y=1
3)2(6x+4y)=3(5x+2y)
12x+8y=15x +6y
12x-15x= 6y-8y
-3x= -2y
3x=2y
x/y= 2/3
4)3(5x-4y)=7(2x-y)
15x -12y =14x -7y
15x-14x = -7y +12y
x= 5y
x/y= 5