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Solve : `6(log_x2-(log_4x)+7=0.` |
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Answer» `6(log_x2 - log_4x)+7 = 0` `=>6(log_2 2/(log_2 x) - log_2x/log_2 4) +7 = 0` `=>6(1/(log_2 x) - log_2x/2) +7 = 0` Let `log_2x =t`, then our equation becomes, `=>6(1/t - t/2)+7 =0` `=>12-6t^2+14t = 0` `=>3t^2- 7t -6 =0` `=>3t^2- 9t + 2t -6 =0` `=>(t-3)(3t+2) = 0` `=>t = 3 or t = -2/3` `=>log_2 x = 3 or log_2 x = -2/3` `=>x = 2^3 or x = 2^(-2/3).` |
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