Is -7+9=-9+7 true, false, or open.
is 4x-3=19 true, false, or open.
which of the following is a solution to the equation 16=4x-4?
-5
-4
5
16
an art student wants to make a model of the classroom. the length off the classroom is 2.4 times its width of the model.
17.5 in
20.5 in
83.6 in
100.8 in
use mental math to determine the solution to x/3=24.

1. This is false. You can interchange terms in addition because of Commutative Property but you are not allowed to interchange the signs of the numbers. 

2. This is neither true nor false. So, this is open. We cannot tell if it's true or false because it is an algebraic equation and we are not given a context behind it.

3. 
16 = 4x - 4
16 = 4(x-1)
x - 1 = 16/4 = 4
x = 4 +1
x = 5

4. Let the width be x. That means that the length is 2.4x. We are missing with information. However, we could only reach this far. There is no further details on the perimeter or area. So, I can't solve this part because the restrictions are open.

5. For this, you have to cross-multiply. The x would be isolated on one side, then the other would be 24*3. That means x= 24*3 = 72

The first one is correct