Question

As raízes da equação x²-7x+10=0 é :

a)2
b)5
c)-5,-2
d)2,5

Answer 1

$x^{2} -7x+10=0\\\\\\ a=1;b=-7;c=10\\\\\\ \Delta=b^2-4ac\to \Delta=(-7)^2-4*1*10\to \Delta=49-40\to \Delta=9\\\\\\ x= \frac{-b+- \sqrt{\Delta} }{2a} \to x= \frac{-(-7)+- \sqrt{9} }{2*1} \to x= \frac{7+- 3 }{2} \to \\\\\\ x'= \frac{7+ 3 }{2} \to x'= \frac{10 }{2} \to x'=5\\\\\\ x''= \frac{7- 3 }{2} \to x''= \frac{4 }{2} \to x''=2\\\\\\ S=(2;5)$


Resposta Correta: Letra D) 2;5