How many of the relations are functions? I’m mainly debating if the first and fourth graphs are functions or not...

A relation f(x) is a function only when there is not two different values in the range that are related to the same value in the domain.

This means that does not exist y1 and y2 such:

f(x1) = y1

f(x1) = y2

if this happens, f is not a function.

Upper graphs, from left to right.

the first graph is a constant line, this is a function f(x) = c.

The second graph is not a function.

The third graph is not a function

the fourth graph is a function

the fourth graph is a function

the fifth graph is not a function.

From the lower ones:

The set of data can be a function

y = 2x^2 - 3 is a function.

The diagram with two circles is not a function (there are more than one output for some imputs)

The last table is a function

$450

step-by-step explanation:

first, you have to multiply 150x2=300

next, you have to add 150+300= 450