Question

Determine as raízes da função: f(×)= 3x²+4×-15=0 ?

Answer 1

$3x^{2} + 4x - 15 \\ {3x}^{2} + 9x - 5x - 15 \\ 3x(x + 3) - 5(x + 3) \\ y = 3x - 5 \: e \: x + 3$

Answer 2

f(x) = 3X^2 + 4X - 15 = 0

a = 3 ; b = 4 ; c = -15

FORMULA DELTA :
~~~~~~~~~~~~~~~~~
D = b^2 - 4 * a * c

D = (4)^2 - 4 (3) (-15)

D = 16 - 12 (-15)

D = 16 + 180

D = 196

FORMULA DE BRASKARA :
~~~~~~~~~~~~~~~~~~~~~~~~
X = - b + ; - \|D
......._________
...............2a

X = - (4) + ; - \|196
.......___________
.................2(3)

X = = - 4 + ; - 14
..........________
..... .............6

X1 = - 4 + 14
.........______
................6

X1 = 10
........___..(÷2)
...........6

X1 = 5
.........__
...........3


X2 = - 4 - 14
..........______
................6

X2 = - 18
...........____
...............6

X2 = - 3


C = { - 3 ; 5/3}