Idon't understand how to do number 14

This is quiet simple. i like to use a method my math teacher calls "plug and chug". we know that y= 4x +2
some people call this the substitution method but it has the same concept. now that we know what y equals, we plug it into teh equation:
(4x+2) -x=17
then we "chug it":
4x+2-x=17
then we have to isolate x. add the x's:
5x+2=17
in order to isolate x subtract 2 from both sides:
5x=15
now to isolate again divide both sides with 5:
x=3
so x is 3. bow we plug that into what y is;
y=4 (3) +2
y=14
so:
x=3
y=14
(to double check plug and chug into the first question . if x and y are correct, you will get 17)