The width of the rectangle is 6 cm less than the length, and its perimeter is 40 cm. Find the sides of the rectangle.

1. Imagine that the width is x cm, then the length will be 6 + x cm. If you compose an expression for the perimeter of this figure, from the result we get the following equation:
2 * (x + x + 6) = 40.
Let’s solve the equation. Let’s simplify the left side first:
2 * (2x + 6) = 40,
4x + 12 = 40.
Now move 12 to the right half, we get:
4x = 40 – 12,
4x = 28.
All that remains is to divide 28 by a factor of 4 to find out the value of x:
x = 28/4,
x = 7 cm.
2. Now let’s find out the length of this rectangle:
6 + 7 = 13 cm.
Answer: as a result, we got that the length of the figure is 13 cm, and the width is 7 cm.