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Find:\( 6^{x}+9^{x}=2^{2 x+1} \) |
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Answer» 6x + 9x = 22x + 1 ⇒ 32x + 3x.2x = 22x + 1 ⇒ 32x + 2.3x .\((\frac{2^x}2)+\frac{2^{2x}}4\) = 22x+1 + \(\frac{2^{2x}}4\) ⇒ (3x + \(\frac{2^x}2\))2 = 22x\((2+\frac14)\) (\(\because\) a2 + 2ab + b2 = (a + b)2) ⇒ (3x + 2x-1) = 3/2 . 2x = 3.2x-1 ⇒ 3x = 3.2x-1- 2x-1 = 2.2x-1 ⇒ 3x = 2x which is possible only when x = 0 hence, if 6x + 9x = 22x+1 then x = 0 |
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