Answer:
1. [tex]x-(-3)[/tex] is not the same as [tex]x+(-3)[/tex], because the first statement is equal to [tex]x+3[/tex] and the second statement is equal to [tex]x-3[/tex].
The first question is false.
2. The second statement is true, because when we multiply equal signs the result is always positive. In this case, both signs have the same nature, negative and negative, so the result is positive.
3. The expression is [tex]-6^{2}-28 \div 4 + (-9)[/tex]
First, we solve powers and divisons: [tex]-36-7-9[/tex] (notice that the negative sign is outside the square power.
Then, we sum: [tex]-36-7-9=-52[/tex]
Therefore, the right answer is -52.
4. The equation is [tex]-2x+6=-20[/tex]
Solving for [tex]x[/tex]
[tex]-2x=-20-6\\x=\frac{-26}{-2}\\ x=13[/tex]
So, the answer is 13.
5. The expression is [tex]x-(-9)=-14[/tex]
So,
[tex]x-(-9)=-14\\x+9=-14\\x=-14-9\\x=-23[/tex]
6. The function is [tex]f(x)=2x-9[/tex], if [tex]x=3[/tex], then [tex]f(3)=2(3)-9=6-9=-3[/tex].
Therefore, the statement is true.
7. False, beacuse the domain refers to the input values and y-values refers to output values. So, they don't means the same thing.
8. This statement is true, because to function be a function, first it has to be a relation, because a function must relate two sets to be one.
