Define the concept stress and state three ways in which the youth could effectively manage stress on arrival at the examination room ​

s = -9

Solution:
18-7s=-9s to -7s=-9s-18 (change the sign of the constant [18] and then move it to the right)

Now move the variable (-9s) to the left side and change its sign as well (now it's just +9s)

Now we have -7s + 9s= -18

Combine the like terms (-7s+9s)

Now we have 2s= -18

And then divide both sides of the equation by two (which equals s = -9)

And then you have your answer, s = -9

Hope you have a great day, God bless! :)