Question

At a party, 4 identical tables are placed side by side as shown. The dimensions of one table are given.

2.5x - 3 and x
Which expressions represent the perimeter of the rectangle formed by all the tables together? Choose all that apply.

10x - 12 + x + 10x - 12 + x
8(2.5x - 3) + 5x
2(10x - 12) + 2x
4(2.5x - 3) + x
2(11x - 12)

*There is more than one answer. Please look at the image and please tell me is I’m correct in the ones I chose*

Answer 1

The answer is the first choice: 10x - 12 + x + 10x - 12 + x

Explanation:

Let the length of a table 2.5x - 3 and let the width of the table be x.

Four tables with identical dimensions are placed together.

So we can say that width of the new table formed by placing the four tables side to side will be the same as the width of one table, that is x.

And the two sides of the new table which will represent the width will be the width of one table at one end and the width of the table at the other end, that is x + x.length

Now as we saw before there are are two widths which are part of the perimeter there are also two lengths which are part of the perimeter.

The perimeter of a table is given by (2 × length) + (2 × width).

Now one length of the new table will be equal to (4 × length of one table) = 4 × (2.5 x - 3) = 10x -12

Therefore perimeter of the new table is given from the formula of the perimeter = Length + width + Length + width

= 10x - 12 + x + 10x -12 + x