You know if something is a function or not because the X will never be used twice in a set. If it is, then it's not a function.
A. Uses -1 twice
B. Uses Nothing twice (good)
C. Uses 0 twice
D. Uses 0 twice
B is your answer
6x4=24
Multiplication is just repeating addition! For example, you can use repetitive (repeating) addition to solve 6x4.
6+6+6+6=24
I added 6 4 times to get to 24. I added it four times because you are multiplying 6 by 4! I am adding 6 (the first number) 4 times (the second number)!
Other examples:
1 x 7=7 because 1+1+1+1+1+1+1=7
2x2=4 because 2+2=4
I hope this helped! :)
275=25x+100 is the correct equation for the number of months it will take for wade to save $275