Mejor respuesta

Vicky51
8

1) 4x ^ 2 + 28 = 428

4x ^ 2 = 428 - 28

4x ^ 2 = 400

x ^ 2 = 100

x1 = - 10 x2 = 10

2) x ^ 2 + x = 30

x ^ 2 + x - 30 = 0

X = - 1 + - √1² - 4(1)( - 30) / 2(1)

X = - 1 + - √1 + 120 / 2

X = - 1 + - √121 / 2

X = - 1 + - 11 / 2

X = - 1 + 11 / 2

X = - 1 - 11 / 2

X₁ = - 6

X₂ = 5

3)x² - x = 30

x² - x - 30 = 0

X = - 1 + - √1² - 4(1)( - 30) / 2(1)

X = - 1 + - √1 + 120 / 2

X = - 1 + - √121 / 2

X = - 1 + - 11 / 2

x = 1 - 11 / 2

x = 1 - 11 + 2

x₁ = 6

x₂ = - 5.