Question

va rog cat mai repede dau coroana ​

Answer 1

l)

$log_{2}( {x}^{2} + 4) = 3 \\ {2}^{3} = {x}^{2} + 4 \\ 8 = {x}^{2} + 4 \\ {x}^{2} = 4 \\ {x}^{2} = {2}^{2} \\ x = 2$

o)

$log_{x}(2 {x}^{2} - 3x - 4 ) = 2 \\ {x}^{2} = 2 {x}^{2} - 3x - 4 \\ {x}^{2} - 3x - 4 = 0 \\ delta = 9 + 16 = 25 \\ x1 =( 3 + 5) \div 2 = 4 \\ x2 = (3 - 5) \div 2 = - 1$