16. A volunteer made m muffins for a bake sale. After selling 28 muffins, 21 muffins
remained. The equation m - 28 = 21
represents the situation. What is the first
step in writing an equivalent equation to
solve m - 28 = 21?

Adrawer contains 12 identical white socks, 18 identical black socks and 14 identical brown socks. what is the least number of socks you must choose, without looking, to be certain that you have chosen two socks of the same colour?

Select the two pairs of figures that are similar.

The area of a rectangle is 10 cm^2. one side of the rectangle is x cm. express the perimeter of the rectangle in terms of x and show that this rectangle cannot have a perimeter of 12 cm. the perimeter of the rectangle in terms of x is __ cm