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

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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:

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

$14r^2 + 35r + 21$

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