Question

The area of a rectangle has decreased by 2%.

Answer 1

Answer:

The other side was decreased to approximately .89 times its original size, meaning it was reduced by approximately 11%

Step-by-step explanation:

We can start with the basic equation for the area of a rectangle:

l × w = a

And now express the changes described above as an equation, using "p" as the amount that the width is changed:

(l × 1.1) × (w × p) = a × .98

Now let's rearrange both of those equations to solve for a / l.  Starting with the first and easiest:

w = a/l

now the second one:

1.1l × wp = 0.98a

wp = 0.98a / 1.1l

1.1 wp / 0.98 = a/l

Now with both of those equalling a/l, we can equate them:

1.1 wp / 0.98 =  w

We can then divide both sides by w, eliminating it

1.1wp / 0.98w = w/w

1.1p / 0.98 = 1

And solve for p

1.1p = 0.98

p = 0.98 / 1.1

p ≈ 0.89

So the width is scaled by approximately 89%

We can double check that too.  Let's multiply that by the scaled length and see if we get the two percent decrease:

.89 × 1.1 = 0.979

That should be 0.98, and we're close enough.  That difference of 1/1000 is due to rounding the 0.98 / 1.1 to .89.  The actual result of that fraction is 0.89090909...  if we multiply that by 1.1, we get exactly .98.