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Question
If 3x + 1 = 9x - 3 , find the value of 21 + x.
Sum
Solution
3x + 1 = 9x - 3
⇒ 3x x 3 = ( 32 )x - 3
⇒ 3x x 3 = `3^(2x)/3^6`
⇒ `3^6 xx 3 = 3^(2x)/3^x `
⇒ `3^7 = 3^x`
⇒ x = 7
⇒ `2^( 1 + x ) = 2^( 1 + 7 ) = 2^8 = 256`
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Solving Exponential Equations
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