How do you multiply #(2r+3)(7r+7)#?

Question

4550 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2017-06-06T14:25:18

See below.

#(2r + 3) (7r + 7)#

#=7r(2r + 3) +7(2r + 3)#

#= 14r^2 + 21r + 14r + 21" "# (Collect like terms)

#=14r^2 + 35r + 21" "# (Add like terms, which are #27r + 14r#)

That's the answer.

Answer 2 · 2017-06-06T14:26:48

See a solution process below:

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

#(color(red)(2r) + color(red)(3))(color(blue)(7r) + color(blue)(7))# becomes:

#(color(red)(2r) xx color(blue)(7r)) + (color(red)(2r) xx color(blue)(7)) + (color(red)(3) xx color(blue)(7r)) + (color(red)(3) xx color(blue)(7))#

#14r^2 + 14r + 21r + 21#

We can now combine like terms:

#14r^2 + (14 + 21)r + 21#

#14r^2 + 35r + 21#