Answer:
9
Explanation:
Based on the algebraic rules for subtracting negative numbers,
when you subtract a negative number, the two negative signs cancel out and instead becomes an addition sign.
For example:
a - -b = a+b
-a - -b = -a + b
Therefore, following this rule,
the equation -51-(-60)
will change the -(-60) into a +60, so
-51 + 60
60-51 = 9