Draw two rectangles. The first has length 6 and width 9. The second has length 3x and width 9. Write at least three different expressions for the sum of the areas of the rectangles.

(1)

And using factorization  (common factor) we can do this:

(2)

(3)

Step-by-step explanation:

In the figure attached we see the two triangles required one with a length of 6 and a width of 9 and the other with a length of 3x and width of 9.

For the first rectangle we know that the area can be founded with this formula:

And for the second rectangle the area can be founded similar like this:

And since we are interested in the sum of the two areas we have this:

We need a 3 different expression for the sum of the areas so we can do this:

(1)

And using factorization (common factor)  we can do this:

(2)

(3)

because linear equations are a lot simpler than quadratics equations, and linear equations formula is a lot easier to memorize. that's why i think they're harder.

-2x + 7 = 7

subtract 7 from both sides.

-2x = 0

divide both sides by -2.

x = 0