Question

Considere a equação 2x² - 2x - 12 =0

a) Calcule o valor de Δ = b² - 4 .a.c.

b) Determine o valor de x = - b + √Δ
2.a

c) Calcule o valor de x = - b - √Δ
2.a

Answer 1

$2x^2-2x-12=0\\\\\dfrac{2x^2-2x-12}{2}=\dfrac{0}{2}\\\\x^2-x-6=0\\\\\\a=1;\ b=-1;\ c=-6\\\\\\a)\ \Delta=b^2-4\cdot a \cdot c\\\\\Delta=(-1)^2-4\cdot 1\cdot (-6)\\\\\Delta=1+24\\\\\boxed{\Delta=25}\\\\\\b)\ x=\dfrac{-b+\sqrt{\Delta}}{2\cdot a}\\\\\\x=\dfrac{-(-1)+\sqrt{25}}{2\cdot(1)}\\\\\\x=\dfrac{1+5}{2}\\\\\\\boxed{x=3}\\\\\\c)\ x=\dfrac{-b+\sqrt{\Delta}}{2\cdot a}\\\\\\x=\dfrac{-(-1)-\sqrt{25}}{2\cdot(1)}\\\\\\x=\dfrac{1-5}{2}\\\\\\\boxed{x=-2}$

Answer 2

                   2
  delta =     2-4.(2).(-12)= 4+94 =100
b) -(-2)+/-50/2.2= 2+50/4=13 
c) -(-2)-50/2.2= 2-50/4= 12
espero ter te ajudado