Answer:
(-4).(-4) = 4^2
Step-by-step explanation:
First, some rules that we need to remember:
if A is a positive number, then:
-A = (-1)*A
Also:
A*A = A^2
We also should remember that we can multiplicate in any order we want, this is:
A*B*C = (A*B)*C = A*(B*C)
And we also can change the order of the numbers:
A*B = B*A
And finally, we need to remember the sign rules for multiplication.
(+)*(+) = (+)
(+)*(-) = (-)
(-)*(+) = (-)
(-)*(-) = (+)
Ok, now let's look at our expression.
(-4)*(-4)
First, we can rewrite this as:
( (-1)*4)*((-1)*4)
And we can rearrange the numbers to:
(-1)*(-1)*4*4
Now let's multiplicate the first two ones, because of the sign rule, we know that the outcome will be positive, and 1 times 1 is equal to 1,
(-1)*(-1) = 1
Then:
(-1)*(-1)*4*4 = 1*4*4 = 4*4
And we know that when a number is multiplied by itself we can rewrite it as:
4*4 = 4^2
Then:
(-4).(-4) = 4^2
The simplified expression is 4^2
