# Solving $17+4h+2=1-5h$. Why is $h=18$ incorrect?

I am learning Algebra on Khan Academy and have a question on solving equations with variables on both sides that I know is basic but can't seem to find the answer to, so hoping someone could clarify.

Given the following equation and solving for $$h$$;

$$17+4h+2=1-5h$$

My first step is to combine the like terms, so $$17+2$$;

$$19+4h=1-5h \tag1$$

Now for the second step, I want to eliminate the variable on one side. I have two options and can get rid of the $$5h$$ or $$4h$$. Most advice online point to targeting the smallest number first ($$4h$$);

$$19+4h-4h=1 - 5h - 4h \tag2$$ $$19=1-1h \tag3$$

However that appears incorrect and the correct answer according to Khan Academy is $$-2$$. They have opted to eliminate the $$5h$$ instead;

$$19+4h=1-5h \tag4$$ $$19+9h=1 \tag5$$ $$9h=-18 \tag6$$ $$h=\frac{-18}{9} \tag7$$ $$h=-2 \tag8$$

Both answers appear correct ($$h=18$$ and $$h=-2$$).

Why would $$h=18$$ be incorrect? Is this an error with Khan Academy or am I missing something?

I've figured out my error, $$1-5h-4h$$ is not $$1-1h$$ but $$1-9h$$. It then resolves $$h=-2$$!
$$17+4(-2)+2=1−5(-2)\equiv11=11$$
$$17+4\cdot18+2=1−5\cdot18\not\equiv91=-89.$$