Question

falera me ajudem aqui :

 

Determine os valores reais das incógnitas em cada uma das eguações 

 

Answer 1

$\frac{4 x^{2} }{3} +5 x=0 --->mmc=3$

$4 x^{2} +15 x = 0 -->x(4x+15) = 0$

$x = 0 --> 4x+15=0-->4x=-15--> x=\frac{-15}{4}$
_____________________________________________________
d) $\frac{7(t+2) ^{2} }{2} =81$

$7(t+2) ^{2} =162$

$7( t^{2} +4t+4)=162 ---> 7t ^{2} +28t+28=162$

$7 t^{2} +28t+28-162=0-->7t ^{2} +28t-134=0$

$\frac{-28+/- \sqrt{784+3752} }{14} = \frac{-28+/- \sqrt{4536} }{14} = \frac{-28+/-67,35}{14} =$

$T1 = \frac{(-28-67,35)}{14} = \frac{-95,35}{14} =-6,81$

$T2 = \frac{(-28+67,35)}{14} = \frac{39,35}{14} = 2,81$