Answer:
180 degrees.
Step-by-step explanation:
Because the angle at the circumference is 90 degrees the arc joining the 2 other points = 180 degrees.
So x = 360 - 180 = 180 degrees.
So :

?
First, you want to bring everything together on the top of the fraction.
12=24/2 so you can have

Add like terms -- 12 +24 = 36

Now we are at

Which is the lowest possible simplified version while remaining at exact value.
Feel free to check my math! I kinda did this off the top of my head.
Question 1: h+4= how many kids in history class.
I think this cause it says to represent the # of kids in the English class with the varible h. there are 4 more kids in the history class for you just add four to the English class( h). this may be wrong tho
question 2: 57+4= 61.
you just input the 57 where the h (# of kids in English class) cause it need to figure out how many are in history and their are just four more kids. I think
also sorry if I suck at explaining things, this makes sorta sense
First, multiply -6*-5. This equals (positive) 30 because the negative signs cancel out.
This leaves you with:
30+12
Doing the addition leaves you with 42.
The answer is 42.
I hope this helps :)