Please help, very confused.

  see below

Step-by-step explanation:

We'll refer to the functions by number, starting at the left.

1. This is a recursively-defined function with each term differing from the one before by a constant. A constant difference between terms means the function is a linear function.

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2. This function is defined by an equation that has the variable in the exponent. That makes it an exponential function.

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3. The differences of adjacent Values are not constant, nor do adjacent Values have a common ratio. This function is neither linear nor exponential. (Second differences are constant, so it is a quadratic function.)

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4. Adjacent values have a common ratio: 9/6 = 13.5/9 = 1.5. That means this function is an exponential function.

step-by-step explanation:

step 1: solve one of the equations for one of the variables. let's solve the first equation for y:

step 2: substitute that equation into the other equation, and solve for x.

step 3: substitute x = 4 x = 4 x=4 into one of the original equations, and solve for y.