Question

va rog cat mai repede dau coroana ​

Answer 1

f)

$log_{2}(2 {x}^{2} - 1) = log_{2}(5x - 4) \\ 2 {x}^{2} - 1 = 5x - 4 \\ 2 {x}^{2} - 5x + 3 = 0 \\ delta = 25 - 24 = 1 \\ x1 = (5 + 1) \div 4 = \frac{6}{4} = \frac{3}{2} \\ x2 = (5 - 1) \div 4 = 1$

h)

$log_{2}( {x}^{2} + 3 ) = log_{2}(2 {x}^{2} + x + 1 ) \\ {x}^{2} + 3 = 2 {x}^{2} + x + 1 \\ {x}^{2} + x - 2 = 0 \\ delta = 1 + 8 = 9 \\ x1 = ( - 1 + 3) \div 2 = 1 \\ x2 = ( - 1 - 3) \div 2 = - 1$