We could use all the help we can get. I can't find the Khan academy videos associated with my work and I'm struggling. any help is appreciatled

#7.

The domain is {-3,0,4}

the range is {-5,0,1,7}

not a function

#8

D={3,6,12,18}

R={5,7,9,10}

not a function

Step-by-step explanation:

First, 7.

the domain is the all of the x values, in numerical order, listed once, even if it repeats.

D={-3,0,4} (notice how -3 is listed twice; despite that, we only list it once)  

the range is all of the y values, in numerical order, listed once, even if the numbers repeat

R={-5,0,1,7}

A function can have the range (y values) repeat, however, the domain (x values) cannot repeat.

Therefore, this is not a function, since -3 is listed twice.

For 8.

The domain, can be listed as

D={3,6,12,18}

And the range as

R={5,7,9,10}

Notice how it says that if 6 is the input (x), the output (y) can be 5 or 10. Since we said the domain CANNOT repeat, this isn't a function.

Hope this helps!

2x^2+5x+17

your welcome. : )