Question

determine as raizes da equação x^2-8x= -7

Answer 1

$x^{2} -8x=-7$
$x^{2} -8x+7= 0$
Aplica Baskara 
Δ=$b^{2} -4.a.c$
Δ= 8^{2}-4(1).(7)[/tex]
Δ= 64-28
Δ= 36
 utiliza a segunda formula x=$\frac{(-b)+- \sqrt{36} }{2.a}$
$x= \frac{8+-6}{2}$
x'=$\frac{8+6}{2} = \frac{14}{2} =7$
x''=$\frac{8-6}{2} = \frac{2}{2} = 1$
 
Raizes: $\left \{ {{x'=7} \atop {x''=1}} \right.$