Question

9x2-30x+25=49 Como resolver?

Answer 1

9x2-30x+25=49

18-30x+25=49

18-30x=49-25

18-30x=24

30x=24-18

30x=6

x=6/30

Answer 2

OI

9x² - 30x + 25 = 49

9x² - 30x + 25 - 49 = 0

9x² - 30 x - 24 = 0

a = 1

b = - 30

c = - 24

1) Calculando o Δ:

Δ = b2 - 4.a.c

Δ = -302 - 4 . 9 . -24

Δ = 900 - 4. 9 . -24

Δ = 900 + 864

Δ = 1764

Há 2 raízes reais.

2) Aplicando Bhaskara:

x = (-b +- √Δ)/2a

x' = -(-30 + √1764)/2.9

x’ = + 30 + 42/18

x' = 72 / 18 : 18

x' = 4

x'' = -(-30 - √1764)/2.9

x”= + 30 – 42/18

x'' = -12 / 18 : 6

x'' = - 2/3

S = { x' = 4 e x" = - 2/3}

Bons estudos.