There is a rectangle with a width of 5x and a length of x + 4. How do you find the area of the rectangle?

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Answer 1 · 2016-05-23T15:26:00

$5x^2 + 20x$

The area of a rectangle is given by the product of its width by its length, therefore, $5x * (x+4) = 5x * x + 5x * 4 = 5x^4 + 20x$ //

Answer 2 · 2016-05-23T15:26:11

$"area "= 5x^2+20x$

area is width multiplied by length

Length given as $x+4$
Width given as $5x$

Let area be $a$
'~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

So area is width multiplied by length $" "->a=5x xx (x+4)$

Normally written as $a=color(blue)(5x)color(brown)((x+4))$

We multiply everything inside the bracket by $color(blue)(5x)$

So we have:

$a=color(brown)((color(blue)(5x xx)x )+(color(blue)(5x xx)4)$

$a=5x^2+20x$

$color(red)("As we do not know the value of " x " we can not take this any further")$