Question

preciso de uma ajuda resposta da equação do segundo grau ?
x²-7x+12=0

Answer 1

x² - 7x + 12 = 0    a) 1 b) - 7 c) 12
Δ = b² - 4 . a . c
Δ = -7² - 4 . 1 . 12
Δ = 49 - 48
Δ = 1
 - b +/- √Δ / 2 . a
- ( - 7 ) +/- 1 / 2 . 1

x' = 7 + 1 /2 = 8/2 = 4

x''= 7 - 1 /2 = 6/2= 3

Answer 2

$x^2-7x+12=0\\\\ a=1;\b=-7;\ c=12\\\\\\ \Delta=b^2-4ac\to \Delta=(-7)-4.1.12\to \Delta=48-48\to \boxed{ \Delta=1}\\\\ x' \neq x''\\\\\\ x= \dfrac{-b\pm \sqrt{ \Delta} }{2a} \to ~~ x= \dfrac{-(-7)\pm \sqrt{ 1} }{2.1a} \to ~~ x= \dfrac{7\pm 1}{2} \to \\\\\\ x'= \dfrac{7+ 1}{2} \to ~~ x'= \dfrac{8}{2} \to ~~ \boxed{x'=4}\\\\\\ x''= \dfrac{7- 1}{2} \to ~~ x''= \dfrac{6}{2} \to ~~ \boxed{x''=3}\\\\\\\\ \boxed{\boxed{S=\{3~;~4\}}}$