Question

Qual o valor de f x = 2x ao quadrado + 5x + 1​

Answer 1

Resposta:

$x = \frac{ \sqrt{17} }{4 \ } + \frac{5}{4 }$

Explicação passo-a-passo:

Solve for x over the real numbers:

2 x^2 + 5 x + 1 = 0

Divide both sides by 2:

x^2 + (5 x)/2 + 1/2 = 0

Subtract 1/2 from both sides:

x^2 + (5 x)/2 = -1/2

Add 25/16 to both sides:

x^2 + (5 x)/2 + 25/16 = 17/16

Write the left hand side as a square:

(x + 5/4)^2 = 17/16

Take the square root of both sides:

x + 5/4 = sqrt(17)/4 or x + 5/4 = -sqrt(17)/4

Subtract 5/4 from both sides:

x = sqrt(17)/4 - 5/4 or x + 5/4 = -sqrt(17)/4

Subtract 5/4 from both sides:

Answer: |

| x = sqrt(17)/4 - 5/4