What’s number one and how do you do it

I'm assuming you mean #10?

So we're given this equation:



In this equation, we a variable of b. We want to solve for b by isolating it, or setting it alone. We see that on the side with b on it, it is being subtracted by 5. We want to the opposite in order to isolate b.

Remember that when you do one thing to one side of the equation, you must do it to the other side as well. We can add 5 on both sides to cancel out the negative 5 on the left.



Therefore we know that b does not equal -10, which can be represented as:



So you have to (a) color the hair yellow.