How is subtracting -4x from 9x similar to subtracting -4 from 9?

You are subtracting four of one thing from nine of it, even if one is four of x and the other is four ones, the actual number four. It's like doing math with strawberries like people do to explain it to little kids, but instead of strawberries, it's a placeholder for an unknown but constant value.

-7

step-by-step explanation:

x^2 + 18x + 74 = (x + 9)^2 - 81 + 74

= (x + 9)^2 - 7.

so q = -7.

circumference divided by 3.141592654 then timesthe radius twice

step-by-step explanation:

circumference divided by 3.141592654 then timesthe radius twice