<h3>
It is a function</h3>
Why? Because each input maps to <u>exactly one</u> output. The input oval represents the domain (set of all possible inputs). The output oval is the range, which is the set of all possible outputs. If we had something like the input 0 mapping to the outputs 2 and 4 at the same time, then we wouldn't have a function.
Answer: 
Step-by-step explanation:

Multiply by the reciprocal in order to get rid of the fraction in the denominator.



Answer:
y = 4x -16
Step-by-step explanation:
y+8= 4(x-2)
y+8=4x-8
y= 4x - 16
Let x = amount of 45% antifreezeLet y = amount of 70% antifreeze EQUATION 1: x + y = 150 (total of 150 gallons mixed) EQUATION 2: .45x + .75y = .55(x + y) Simplify and solve the system of equations Multiply second equation by 100 on both sides to remove the decimals 45x + 75y = 55(x + y) Combine like terms 45x + 75y = 55x + 55y 45x - 55x + 75y - 55y = 0 -10x + 20y = 0 Now we have the following system of equations: x + y = 150 -10x + 20y = 0 Multiply the first equation by -10 to get opposite coefficients for x; add the equations to eliminate x 10x + 10y = 1500 -10x + 20y = 0 ------------------------------ 30y = 1500 Solve for y 30y = 1500 y = 50 Since the total mixed gallons is 150, x = 150 - 50 = 100 So we need 100 gallons of the 45% antifreeze and 50 gallons of the 70% antifreeze