Question

Resolva as equações: a) x2-3x-10=0b) 4x2+8x=0c) 5x2+3x+5=0d) 9x2-12x+4=0e) x2-8x+12=0f)x2-289=0g)2x2-288=0h) x.(x -2)=2.(x+6)

Answer 1

a) x² - 3x - 10 = 0

x = $\frac{-(-3) + \sqrt{-3^{2} - 4*1*(-10)}}{2*1}$

x = $\frac{-(-3) - \sqrt{-3^{2} - 4*1*(-10)}}{2*1}$

x = −2, x = 5

b) 4x² + 8x = 0

x (4x + 8) = 0

x = −2, x = 0

c) 5x² + 3x + 5 = 0

x = $\frac{-3 + \sqrt{3^{2} - 4*5*5}}{2*5}$

x = $\frac{-3 - \sqrt{3^{2} - 4*5*5}}{2*5}$

x = −91√i + 310, x = 91√i − 310

d) 9x² - 12x + 4 = 0

x = $\frac{-(-12) + \sqrt{(-12)^{2} - 4*9*4}}{2*9}$

x = $\frac{-(-12) - \sqrt{(-12)^{2} - 4*9*4}}{2*9}$

x = $\frac{<strong>2</strong>}{<strong>3</strong>}$

e) x² - 8x + 12 = 0

x = $\frac{-(-8) + \sqrt{(-8)^{2} - 4*1*12}}{2*1}$

x = $\frac{-(-8) - \sqrt{(-8)^{2} - 4*1*12}}{2*1}$

x = 6, x = 2

f) x² - 289 = 0

x = $\sqrt{289}$

x = −17, x = 17

g) 2x² - 288 = 0

x = $\sqrt{\frac{288}{2}}$

x = −12, x = 12

h) x (x - 2) = 2 (x + 6)

x² - 2x = 2x + 12

x² - 4x + 12 = 0

x = $\frac{-4 + \sqrt{4^{2} - 4*1*12}}{2*1}$

x = $\frac{-4 - \sqrt{4^{2} - 4*1*12}}{2*1}$

x = 6, x = −2

Informem caso haja algum erro.