B) Given y= 5x – 4, enter the value of x when y = –39

X=-7
Substitute-39 where y is seen in the question this will result in the following
-39=5x-4
Then you need to isolate 5x you do this by doing the opposite and removing the 4 so you would instead add 4 resulting in
-35=5x
To finish the question you would again aim to isolate x by dividing by 5 this would leave you with the end result of
X=-7
Below is all of the work together remember that you do to one side you do to the other
-39=5x-4
+4 +4
-35=5x
/5 /5
-7=5