Question

3x ao quadrado - 3x - 4 =0

Answer 1

$3x {}^{2} - 3x - 4 = 0$
$x = \frac{ - ( - 3) + - \sqrt{( - 3) {}^{2} - 4 \times 3 \times ( - 4)} }{2 \times 3}$
$x = \frac{3 + - \sqrt{9 + 48} }{6}$
$x = \frac{3 + - \sqrt{57} }{6}$
$x = \frac{3 + \sqrt{57} }{6}$
$x = \frac{3 - \sqrt{57} }{6}$

$x1 = x = \frac{3 - \sqrt{57} }{6}$
$x2 = x = \frac{3 + \sqrt{57} }{6}$

Answer 2

3x²-3x-4=0
a=3  b=-3  c=-4

Δ= b²-4·a·c
Δ= (-3)²-4·3·(-4)
Δ= 9 -12·(-4)
Δ= 9 + 48
Δ= 57

x'= -b+√Δ/2·a
x'= -(-3)+√57/2·3
x'= 3+√57/6

x"= -b-√Δ/2·a
x"= -(-3)-√57/2·3
x"= 3-√57/6



Se √57≈ 7,5:
x'≈ 3+7,5/6
x'≈ 10,5/6
x'≈ 1,75

x"≈3-7,5/6
x"≈ -4,5/6
x"≈ -0,75