Perform the indicated operation: $( 7 c + 3 d ) ( 7 c - 3 d )$
A) $49 c ^ { 2 } - 9 d ^ { 2 }$
B) $14 c ^ { 2 } - 6 d ^ { 2 }$
C) $49 c ^ { 2 } - 2 c d - 9 d ^ { 2 }$
D) $49 c ^ { 2 } - 42 c d + 9 d ^ { 2 }$

Question

Quizplus · Accepted Answer

Using the FOIL method, we get: 
$$ (7c+3d)(7c-3d) = (7c)^2 - (3d)^2 = 49c^2 - 9d^2 $$ The other answer choices include additional terms that are not present in the original expression.

Perform the Indicated Operation (7c+3d)(7c−3d)( 7 c + 3 d ) ( 7 c - 3 d )(7c+3d)(7c−3d)

Perform the Indicated Operation $( 7 c + 3 d ) ( 7 c - 3 d )$