Question

1) O conjunto verdade em IR da equação 1=-10-25x² é: 



 2 )x²-3x = 10 admite a ?

Answer 1

$1)~~-25 x^{2}-10=1\\ -25 x^{2} =1+10\\ -25 x^{2} =11\\ x^{2} = -\frac{11}{25}\\\\ x= \sqrt{- \frac{11}{25} }\\\\ x~nao~admite~raizes~reais$


$2)~~ x^{2} -3x=10\\ x^{2} -3x-10=0\\\\ \Delta=b ^{2}-4ac~\to\Delta=(-3) ^{2}-4*1*(-10)\to~\Delta=9+40~\to~\Delta=49$

$\boxed{x= \frac{-b\pm \sqrt{\Delta} }{2a}}\\\\\\ x= \frac{-(-3)\pm \sqrt{49} }{2*1}~\to~x= \frac{3\pm7}{2}~\to~\begin{cases}x'=\frac{3-7}{2}~\to~x'= \frac{-4}{2}~\to~x'=-2\\\\ x''= \frac{3+7}{2}~\to~x''= \frac{10}{2}~\to~x''=5 \end{cases}\\\\ \boxed{S=\{-2,5\}}$

Espero ter ajudado e tenha ótimos estudos xD