Heyyy can somebody answer this please ?

number 9 is c.

im not really sure what 10 is

9. (3,-4) which is C

10.  (8,-4) which is A

For number 9:

I did elimination by taking one of the "answers" so for (3,-4) x=3 and y= -4

i plugged them in the equation so:

-10(3) -3(-4)= -18 **now we just solve**

-30+12 **its +12 because negative and negative= positive**

-30+12= -18

For number 10:

same steps as before i plugged (8,-4) so:

3(8)- (-4)- 28

24+4= 28

b, i believe, but not sure.