Question

a) 4x²- 8 + 2x + 3

b)
$4 x {}^{2} - 8 \times 2x + 3$
c)
$x {}^{2} - 3x + 1 - 2x + 3$
d)
$5 \times x {}^{2} - 3x + 1$
​

Answer 1

a) 4x² - 8 + 2x + 3

4x² + 2x - 8 + 3

4x² + 2x - 5 = 0

delta = b² - 4ac

delta = 2² - 4.(4).(-5)

delta = 4 + 80 = 84

x = ( - b +- raiz de delta ) / 2a

x = ( - 2 +- raiz de 84 ) / 2.4

x = ( - 2 +- raiz de 84 ) / 8

x' = ( - 2 - raiz de 84 ) / 8

x" = ( - 2 + raiz de 84 ) / 8

b) 4x² - 8 . 2x + 3

4x² - 16x + 3 = 0

delta = (-16)² - 4.(4).(3)

delta = 256 - 48 = 208

x = ( - (-16) +- raiz de 208 ) / 2.4

x = ( 16 +- raiz de 208 ) / 8

x' = ( 16 - raiz de 208 ) / 8

x' = ( 16 - raiz de 208 ) / 8x" = ( 16 + raiz de 208 ) / 8

c) x² - 3x + 1 - 2x + 3

x² - 3x - 2x + 1 + 3

x² - 5x + 4

delta = (-5)² - 4.(1).(4)

delta = 25 - 16 = 9

x = ( - (-5) +- raiz de 9 ) / 2.1

x = ( 5 +- 3 ) / 2

x' = ( 5 - 3 ) / 2 = 2 / 2 = 2

x" = ( 5 + 3 ) / 2 = 8 / 2 = 4

d) 5 . x² - 3x + 1

5x² - 3x + 1

delta = (-3)² - 4.(5).(1)

delta = 9 - 20 = - 11

x = ( - (-3) +- raiz de - 11 ) / 2.5

x = ( 3 +- raiz de - 11 ) / 10

x' = ( 3 - raiz de - 11 ) / 10

x" = ( 3 + raiz de - 11 ) / 10