The Addition Property of Equality justifies Emily's first step. She added 9 to both sides, canceling out the minus 9 while keeping the equation equal.
Altho' I can easily guess what you're supposed to do here, I must point out that you haven't included the instructions for this problem.
I'll help you by example. Let's look at the first problem:
"Evaluate 6(z-1) at z-4."
Due to "order of operations" rules, we must do the work inside the parentheses FIRST. Replace the z inside (z-1) with "-4". We obtain
6(-4-1) = 6(-5) = -30 (answer.)
Your turn. Try the next one. If it's unclear, as questions.
Answer:

Step-by-step explanation:
Given that,
Sheila 833 hot dogs every 44 minutes.
We need to find how minutes will take to eat 18 hot dogs.
833 hot dogs = 44 minutes
1 hot dog = (44/833) minutes
For 18 hot dogs,

So, it will take
to eat 18 hot dogs.
Use a^2+b^2=c^2 so 10^2+10^2=c^2 which is 200=c^2 and you could leave it in sqrt form so c=sqrt(200) or you can simplify it to 10sqrt(2) or you can approx the answer which is 14.14
-3 is 3 less than zero. So when you also take ten away, the -3 becomes -13