180 - 53 - 96 = 31°. you know the angles are 53 and 96 degrees because the triangles are congruent via SAS congruency.
Here are a bunch of CORRECT answers. Your answer is in the first pic. I got number 3 wrong, but it still showed the correct answer.
I am assuming 28/0. The short answer is that it is infinity. (Or they may want undefined)
Here is a bit longer explination:
Let's start by taking 28/1, that gives 28. What about 28/0.5 that gives 56, and as we keep decreasing the denominator closer to zero then the quotient will become larger and larger. We we reach zero, the quotient becomes so large that it is considered infinity.
You have to isolate the variable so you need to add 7z and 9 to both sides. You then get y+ 7z+ 9= 7x. Then divide 7x from both sides. The equation becomes x= y/7+ z + 9/7.
I hope this helps love! :)