Answer:
Ques 16)
We have to simplify the expression:

Ques 17)

Ques 18)
Let the blank space be denoted by the quantity 'x'.

Ques 19)
Let the missing quantity be denoted by 'x'.

Answer:To do so, she makes the measurements shown in the figure below.
Step-by-step explanation:
4x + 3 + x - 2 +4x +3 +x - 2
5x + 1 + 4x + 3 + x - 2
5x + 1 + 5x + 1
10x + 2
Divide each term in the numerator by the denominator...
2xy^2-1