17. At the school store, 3 pens and 2 notebooks cost a total of $12, while I pen and 3 notebooks cost a total of $11. This can be represented by the system of equations,
where x stands for the cost, in dollars, of pens, and y stands for the cost, in dollars,
of notebooks.

the five is the numerator

2 equivalent expressions to represent the area of a rectangle and the top is n-3 and the side is 2

area of the rectangle = length * width

given length = n - 3

width = 2

replace it in the area

so area of the rectangle = (n-3) *2

= 2(n-3)

one of the expression is 2(n-3)

to get another expression we distribute 2 inside the parenthesis

2(n-3) is 2n - 6

so another expression is 2n - 6

two equivalent expression are

2(n - 3)   , 2n - 6