Multiply, and then simplify if possible. Assume all variables represent positive real numbers.
-$( 7 \sqrt { x } + 3 ) ( \sqrt { 7 x } - 3 )$
A) $7 x \sqrt { 7 } - 42 \sqrt { x } - 9$
B) $7 x \sqrt { 7 } - 21 \sqrt { x } + 3 \sqrt { 7 x } - 9$
C) $7 x - 9$
D) $7 x - 42 \sqrt { x } - 9$

Question

Quizplus · Accepted Answer

The expression is expanded using the distributive property: $ (7\sqrt{x})(\sqrt{7x}) + (7\sqrt{x})(-3) + (3)(\sqrt{7x}) + (3)(-3) $. Simplifying gives $ 7x\sqrt{7} - 21\sqrt{x} + 3\sqrt{7x} - 9 $.

Multiply, and Then Simplify If Possible (7x+3)(7x−3)( 7 \sqrt { x } + 3 ) ( \sqrt { 7 x } - 3 )(7x​+3)(7x​−3)

Multiply, and Then Simplify If Possible $( 7 \sqrt { x } + 3 ) ( \sqrt { 7 x } - 3 )$