Gr10 math ques? subsitution/elimination

How would I substitute or eliminate this questions?

y = x + 4

y = 2x - 1

Thanks

SUBSTITUTION: since both of the equations start with "y" you can just simply let them equal to one another.
i.e: x+4 = 2x-1
--> get all the pronumerals on one side, and numbers on the other
therefore x= 5
now substitute, x=5 in any one of the equations
y= 5+4 --> y=9
y= 2 x 5 -1 --> y=9

ELIMINATION:
i'd rearrange both equations, so x and y are on one side and the numbers are on the other

x - y = -4 (1)
2x - y = 1 (2)

now you have to see if you can eliminate any values.
if you do equation (1) - equation (2) the "y's" will cancel out, and you'll be left with "x"
(if you want to eliminate "x" first, multiply equation (1) by 2 and then subtract)

therefore (1) minus (2) will give you: -x = -5, x=5
and then again, sub into an equation, and you'll get y= 9