Find the sum of all values of x such that
4 x + 4 1 / x = 1 8 .
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It's like 4 x , 4 1 / x > 0 Hence, 4 x = 2 and 4 1 / x = 1 6 ⇒ x = 2 1 O R 4 x = 1 6 and 4 1 / x = 2 ⇒ x = 2
sir, why did you choose 4^x - 16 = 0
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Dear sir, you may choose 4^x-2=0 => x=1/2
And as same as the other pair.
Any combination is possible to find answer, which receives the same x.
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@Dev Sharma – Me too :D I'm same age as you.
Yup , that's it
How do you prove that these are the only solutions?
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by drawing graph
Was somewhat easier than? Isn't?
Clearly, x = 2 or 1/2.
So, 2 + 0.5 = 2.5
true. Nice question. Is that hardwork? This problem doesnt need hardwork. Good job @Dev Sharma .
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sir, its part of my set, Problems nee HardWork. Please see that set.
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okay @Dev Sharma
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@Nelson Mandela – sir, have you seen that set?
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@Dev Sharma – I am not sir, I am only 15 years old and yes the questions in that set are very good. Keep it up @Dev Sharma .
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4 x + 4 x 1 = 1 8 ⇒ 4 x + 4 x 1 − 1 8 = 0
4 x + 4 x 1 − 1 6 − 2 = 0
⇒ 4 x − 1 6 = 0 ⇒ x = 2
or
4 x 1 − 2 = 0 ⇒ 2 2 × x 1 = 2 1 ⇒ x = 2 1
Take 2 + 2 1 = 2 5