Question

Find an expression which represents the sum of (6x + 9y) and (7x - 4y) in simplest terms.

Answer 1

(6x + 9y) + (7x - 4y)

Remove parenthesis:

6x + 9y + 7x - 4y

Add like terms:

(6x + 7x) + (9y - 4y)

(13x) + (5y)

13x + 5y

(6x + 9y) - (7x - 4y)

Remove parenthesis (keep in mind law of signs)

6x + 9y - 7x + 4y

Add like terms:

(6x - 7x) + (9y + 4y)

(-x) + (13y)

-x + 13y

or

13y - x