By definition
Why?
Look at the function
i understand that an absolute value is the distance on a number line from zero, and that abs(y)=8 would be 8, -8, but when it gets to like abs(c/4)=9, i know you have to make two equations, c/4=9 and c/4=-9, because my sheet says so, but why? i don't understand why the 9 is affected when it is not in the absolute value bars.......