one f.4 question

a.
(3x-8y)/(6x-2y)=-1/2
3x-8y=-1/2*(6x-2y)
3x-8y=-3x+y
3x+3x-8y-y=0
6x-9y=0
2x-3y=0
2x=3y
so,
x:y
=3:2

b.
becausex:y=3:2
so,y=2x/y
2x^2-6y=3(x-1)
2x^2-6y=3x-3
2x^2-6y-3x+3=0
2x^2-6(2x/3)-3x+3=0
2x^2-4x-3x+3=0
2x^2-7x+3=0
2x -1
x -3
----------------
-6x-x=-7x
(2x-1)(x-3)=0
when2x-1=0
X1=1/2
whenx-3=0
X2=3
so,whenx=1/2,y=1/3
whenx=3,y=2

(3x-8y)/(6x-2y)=-1/2
2(3x-8y)=-1(6x-2y)
6x-16y=2y-6x
12x=18y
x/y=18/12
x:y=3:2

y=2x/3
2x^2-6y=3(x-1)
2x^2-6(2x/3)=3x-3
2x^2-4x-3x+3=0
(2x-1)(x-3)=0
x=1/2 , 3
y=1/3 , 2

a)find x:y


(3x-8y)/(6x-2y)=-1/2
-(6x-2y)=2(3x-8y)
-6x+2y=6x-16y
-12x=-18y
x/y=3/2

b)if 2x^2-6y=3(x-1)

((2x^2-6y)/3)+1=x