Answer:
Because +- or - + = -
Step-by-step explanation:
-a + b = - c
a + - b = - c
-a × b = - c
a × - b = -c
Extra references:
-ve ×/+ -ve = +ve
+ve ×/+ -ve = - ve
-ve ×/+ +ve = - ve
+ve ×/+ +ve = +ve
Hope these could solve your problem.
