How many centimeters the perimeter of the rectangle will decrease if its length is reduced

How many centimeters the perimeter of the rectangle will decrease if its length is reduced by 16 cm and the width is left unchanged.

1. Let’s denote by symbols:

a- length of the rectangle (cm);

b – the width of the rectangle (cm);

P1 – perimeter of the rectangle before changes (cm);

P2 – perimeter of the rectangle after changes (cm);

2. We compose the equations:

P1 = 2a + 2b;

P2 = 2 (a – 16) + 2b;

P1 – P2 = 2a + 2b – 2a + 32 – 2b = 32 (cm).

Answer: the perimeter of the rectangle will decrease by 32 cm.