Question

(065.02) Resolva em R -2x2+ 7x -3>_ 0

Answer 1

- 2x^2 + 7x - 3 > 0

a= - 1 b= 7 c= - 3

formula de delta

D = b^2 - 4 a c

D = (7)^2 - 4 (-2) (-3)

D = 49 + 8 (-3)

D = 49 - 24

D = 25

formula de braskara

X = - b - , + \/D
......._________
...............2 a

X = - (7) - , + \/ 25
.......___________
...............2 (-2)

X = - 7 - , + 5
.......________
..............- 4

X' = - 7 - 5
........_____
...........- 4

X' = - 12
........____
..........-4

X = 12
.......__
........4

X' = 3


X" = - 7 + 5
........______
.............- 4

X" = - 2
........___
.........- 4

X" = 2
........___(÷2)
..........4

X" = 1
........__
..........2

S = { 1/2 , 3 }