Question

Encontre as raízes da equação x2-x-20=0

Answer 1

x² -x -20
Δ=b² -4ac
Δ= (-1)²- 4.1.(-20)
Δ= 1 + 80
Δ= 81

x=-b +/- √Δ / 2a
x= -(-1) +/- √81 / 2.1
x'= 1 +9 / 2
x'= 10/2
x'= 5

x''= 1 -9 /2
x''= -8/2
x''= -4

Bons estudos!

Answer 2

Δ = b2 - 4.a.c 
Δ = -12 - 4 . 1 . -20 
Δ = 1 - 4. 1 . -20 
Δ = 81

x = (-b +- √Δ)/2a

x' = (-(-1) + √81)/2*1
x' = 10 / 2
x' = 5

x'' = (-(-1) - √81)/2*1
x'' = -8 / 2
x'' = -4
Paz e luz :)