Answer:
Step-by-step explanation:
I'm assuming that you are solving for x, since there's nothing else you can do with this mathematically.
[tex]\frac{1}{2}x=-9[/tex] and the goal is to get the x all alone. So we have to lose the fraction. Do that by multiplying by the reciprocal of 1/2 which is 2/1 (a reciprocal is just a fraction flipped upside down). BUT...because this is an equation, what you do to the left side has to be done to the right side too. Like this:
[tex](\frac{2}{1})\frac{1}{2}x=\frac{-9}{1}(\frac{2}{1})[/tex]
On the left, everything cancels out but the x (which is why we do this), and on the right we multiply straight across the top and straight across the bottom to get
[tex]x=\frac{-18}{1}[/tex] which is
x = -18
