Question

Calcule as raízes das equações

a) x² =16
b) x² - 3x = 2x -6

Answer 1

a) $x^2=16$

$x=$ ±$\sqrt{16}$

$x=$ ± $4$

$x_1=4\\x_2=-4$

b) $x^2-3x=2x-6$

$x^2-3x-2x+6=0$

$x^2-5x+6=0$

$\triangle=(-5)^2-4.1.6$

$\triangle=25-24$

$\triangle=1$

$x_1=\frac{-(-5)+\sqrt{1} }{2.1}=\frac{5+1}{2}=\frac{6}{2}=3$

$x_2=\frac{-(-5)-\sqrt{1} }{2.1}=\frac{5-1}{2}=\frac{4}{2}=2$