There is a rule:
One input(x-value) can only have one output(y-value) in order to be a function.
If one input has more than one output, it is not a function.
(This doesn't apply to outputs, one output can have more than one input and still be a function)
The 1st option is not a function because the inputs 9 and 10 have more than one output.
The 2nd option is not a function because the input 3 has more than one output.
The 3rd option is a function because each input only has one output.
The 4th option is not a function because the input 5 has more than one output.
First remember that sum means to add. now think about the equation. we need to find 3 numbers that equal 159 when added together. And they are all consecutive odd numbers. so let's call the first number X. the second number would be X+2 since we have to jump over 1 even number. The third number would be X+4 since we have to jump over 2 even numbers. so now an equation to represent this would be X+(X+2)+(X+4)=159. Add like terms, and remember order of operations. if you need help getting the answers leave me a comment.
I got A, -32, but it has been awhile since I have learned this in my math class. You might want to wait for someone else to verify this answer.
Answer:
x° = 64°
Explaination:
This is a right angled triangle so one of the angle is 90°.
So, x° + 90° = 154° (Exterior angle property)
x° = 154° - 90° = 64°
Therefore x° = 64°