We will begin by writing the area as a sum. This can be done by adding the areas of the smaller rectangles.
A=- 1x+(- 3y)+5+2x^2+6xy+(- 10x)
⇓
A=2x^2+6xy-3y-11x+5
To write the area as a product we have to identify the length of the smaller rectangles. Of the six smaller rectangles, two of them can be factored in only one way.
Notice that both areas have x as a factor. Therefore, their horizontal sides — which they share — must have this length.
Now we have enough information to factor the remaining areas and therefore identify the length of the remaining sides.
Finally, we will add the lengths along the larger rectangle's sides and multiply these sums.
A=(2x+(- 1))(x+3y+(- 5))
⇓
A=(2x-1)(x+3y-5)
