asked 84.9k views
5 votes
Ahmed is solving the following equation for xxx.

2\sqrt[3]{x-7}+11=32
3

x−7

+11=32, cube root of, x, minus, 7, end cube root, plus, 11, equals, 3
His first few steps are given below.
\begin{aligned}2\sqrt[3]{x-7}&=-8\\ \\ \sqrt[3]{x-7}&=-4\\ \\ \left(\sqrt[3]{x-7}\right)^3&=(-4)^3\\ \\ x-7&=-64 \end{aligned}
2
3

x−7


3

x−7


(
3

x−7

)
3

x−7


=−8
=−4
=(−4)
3

=−64


Is it necessary for Ahmed to check his answers for extraneous solutions?
Choose 1 answer:

2 Answers

2 votes

Answer:

no

Explanation:

answered
User Renier Botha
by
7.9k points
2 votes

Answer:

No

Explanation:

An extraneous solution is a root of a transformed equation which is not a root of the original equation because it was not included in the domain of the original equation.

Ahmed is solving
2\sqrt[3]{x-7}+11=3 for x.

His steps were:


\begin{aligned}2\sqrt[3]{x-7}&=-8\\ \sqrt[3]{x-7}&=-4\\ \left(\sqrt[3]{x-7}\right)^3&=(-4)^3\\ x-7&=-64 \end{aligned}

Since cube roots do not give two solutions when solved, it is not necessary to check his answers for extraneous solutions.

answered
User Olovb
by
7.6k points

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