How do you multiply #(ab + xy)(7ab + 9xy)#?

1 Answer
Jul 5, 2017

Answer:

See a solution process below:

Explanation:

To multiply these two terms you multiply each individual term in the left parenthesis by each individual term in the right parenthesis.

#(color(red)(ab) + color(red)(xy))(color(blue)(7ab) + color(blue)(9xy))# becomes:

#(color(red)(ab) xx color(blue)(7ab)) + (color(red)(ab) xx color(blue)(9xy)) + (color(red)(xy) xx color(blue)(7ab)) + (color(red)(xy) xx color(blue)(9xy))#

#7a^2b^2 + 9abxy + 7abxy + 9x^2y^2#

We can now combine like terms:

#7a^2b^2 + (9 + 7)abxy + 9x^2y^2#

#7a^2b^2 + 16abxy + 9x^2y^2#