Answer: y=2.7
Explanation:
Since x=9y and substitution,
plug the 9y in where x is in the equation like so,
9y-5=20
Now get the variable by itself
To do this you add 5 to both sides of the equal sign
5+(-5) cancels out and 20 +5 =25
Now isolate the varaible by dividing 9y from both sides
So, 9y=25
9/9=1 so you leave it as y
and 25/9 is 2.77777
therefore y=2.7