Multiply.
-$$( 5 - 3 \sqrt { 5 } ) ^ { 2 }$$
A) $70 + 30 \sqrt { 5 }$
B) $70 - 30 \sqrt { 5 }$
C) $25 + 9 \sqrt { 5 }$
D) $25 - 9 \sqrt { 5 }$

Name: Multiply. -\[( 5 - 3 \sqrt { 5 } ) ^ { 2 }\] A) $70 + 30 \sqrt { 5 }$ B) $70 - 30 \sqrt { 5 }$ C) $25 + 9 \sqrt { 5 }$ D) $25 - 9 \sqrt { 5 }$
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Question

Quizplus · Accepted Answer

$$( 5 - 3 \sqrt { 5 } ) ^ { 2 } = (5-3\sqrt{5})(5-3\sqrt{5})$$
Using FOIL method, we get:
$$25-15\sqrt{5}-15\sqrt{5}+45=(25+45)-30\sqrt{5}=70-30\sqrt{5}$$
So, the answer is B.

Multiply - (5−35)2( 5 - 3 \sqrt { 5 } ) ^ { 2 }(5−35​)2

Multiply
- $( 5 - 3 \sqrt { 5 } ) ^ { 2 }$