Answer:

Step-by-step explanation:
Given the expression

Remove parentheses: (a)=a

Group like terms

Add similar elements
∵ 
Add similar elements
∵ 
Thus, the equivalent expression in simplified form:

Answer: Your answer is the third one, a function assigns to each input exactly one output.
If you have a true function, there will only be one output for each input, if you had more than one, it isn't a function.
Answer:
1458 sq cm
Step-by-step explanation:
because each dimension of A is 3 tomes each dimension of B, that will mean that both the length and width of B are multiplied by 3 in order to get the length and width of A, so the area of B is length×width=162 and the area of A (in terms of B's dimensions) is 3xlength×3×width=9×length×width=9×162=1458 sq cm