Answer: b = 4 (choice C)
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Work Shown:
[tex]2\sqrt{b} + 5 = 11 - \sqrt{b}\\\\2x + 5 = 11 - x\\\\2x+x = 11 - 5\\\\3x = 6\\\\x = 6/3\\\\x = 2\\\\\sqrt{b} = 2\\\\b = 2^2\\\\b = 4\\\\[/tex]
What I did for a good portion of the early steps is replace [tex]\sqrt{b}[/tex] with x. Then I solved for x like with any normal equation. Once x is isolated, plug in [tex]x = \sqrt{b}[/tex] and isolate b itself.
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Let's check the answer:
[tex]2\sqrt{b} + 5 = 11 - \sqrt{b}\\\\2\sqrt{4} + 5 = 11 - \sqrt{4}\\\\2*2 + 5 = 11 - 2\\\\4 + 5 = 11 - 2\\\\9 = 9 \ \ \ \ \checkmark\\\\[/tex]
The answer of b = 4 is confirmed.
It's always a good idea to check the answer with any equation. This is especially true with square root equations because the solution might be extraneous (meaning that it works in some equations but not in the original starting equation).
