x-2y=0
3x-y^2=0
I would prefer to use the first equation to do the substituting because it's simpler, but you could use the other one if you prefer. First, x-2y=0, add the 2y to both sides which is
x=2y. Take x=2y and substitue it in the equation 3x-y^2=0.
3(2y)-y^2=0
6y-y^2=0
Factor the equation
y(6-y)=0
y=0 or 6-y=0
y=0 or y=6
Now, substitue that in the equation 3x-y^2=0
3x-0^2=0
3x=0
x=0
3x-6^2=0
3x-36=0
3x=36
x=12
So your answer would be x={0, 12} and y={0, 6}
Hope this helps
first make first equation in terms of x
so: x-2y=0
+2y
x=2y
substitute in x into 2nd equation so:
3(2y)-y^2=0
6y-y^2=0
then factorise
y(6-y)=0
therefore y=0 or 6
put both values of y into first equation to find x
x-2*0=0 and x-2*6=0
therefore x= 0 if y=0 and x=12 if y=6
for the method of substitution you have to sub one equation for another so rearange the first equation x-2y=0 for x=2y
and sub x=2y into the second equation so the second equation will be
3(2y) - Y^2=0
6y-y^2=0 take y out
y(6 - y) = 0
therefore y = 0 and y = 6