Because it has a "-" sign in front of it.
7 does not equal negative 7.
-7-(-7)=0
7
Equal negative 14!
A negative... as in (-5) + (-7) = (-12). A negative timesa negative is a positive... as in (-5) X (-7) = (+35)
positive 14
Negative seven Negative 7 -seven -7 (just add a minus sign)
(-9) / (-7) * 7 = 9/7*7 = 9
0.8571
(-4) - (-7) = (-4) + 7 = 3
-7--4=-7+4=-3
1.1429