Find X in Rectangle Area: Solving When Area = 28 and Height = 4

Question

If the area of the rectangle below is equal to 28.

AC = 4

AB = X + 5

Calculate X.

00:00 Find X

00:03 The formula for calculating rectangle area is width(AB) multiplied by length(AC)

00:07 Let's substitute appropriate values according to the given data and solve for X

00:13 Let's properly expand the parentheses

00:17 Isolate X

00:21 And this is the solution to the question

The area of the rectangle is equal to the length multiplied by the width.

Let's present the known data:

$28=4\times(x+5)$

$28=4x+20$

We'll move 20 to the left side and maintain the appropriate sign:

$28-20=4x$

$8=4x$

Let's divide both sides by 4:

$x=2$