To be a function each x-value (input) should have only one y-value (output). Here you can see when x=2 it has an output of either 5 or 1. Therefore, the relation is NOT a function.
Answer: 
Step-by-step explanation:
Group like terms:

Simplify the arithmetic:

Add 7 to both sides:

Simplify the arithmetic:

Simplify the arithmetic:

Divide both sides by 3:

Simplify the fraction:

Find the greatest common factor of the numerator and denominator:

Factor out and cancel the greatest common factor and the answer will be:

Locate 1 on the x axis. This is the horizontal number line.
Draw a vertical line through 1 on the x axis. Extend this vertical line as far up and down as you can.
Notice how the vertical line crosses the blue curve. Mark this point. Then draw a horizontal line from this point to the y axis. The horizontal line will touch -4 on the y axis. So that means the point (1,-4) is on the curve.
If the input it is x = 1, then the output is y = -4
So that's why the answer is choice A
Answer:
A=B-5
Step-by-step explanation:
Albert is known as the variable A.
Bill is known as the variable B.
If Albert is 5 years younger than Bill. Then the equation will be
a=b-5
The statement will be m∠ABC = m∠GHI.
Reason: ∠ABC ≅ ∠GHI