Explanation:
I don't know what the equations are, but I'll do my best to help
ax² + bx + c
"a" is multiplied by (-4) and (c), as well as 2 in the denominator
"b" is put in front of the equation so, hypothetically speaking, b = -1
-b = -(-1) = 1 so it would turn a positive into a negative and a negative into a positive number.
b is also squared so no matter what it will be positive in √b² - 4ac
"c" is multiplied by (-4) and (a)
If I knew the equations I could help more but this is probably the best I can do.
I hope this helps!