10 minutes I'm pretty sure. My calculations may be off but at least I tried
Answer:
I'm not sure what 15y3 is, but I'll take a guess.
If the only numbers are 15, 3, and -40, then the greatest common factor is 1.
If the only numbers are 15 and 3, then it's three.
If the only numbers are 15 and -40, it would be 5.
-9 cause you’ll be looking at the vertical line
X+3=4 the only answer is x=1 , you write out x+3=4, then you subtract 3 from each side you get x=1
