Question

Решите эти примеры с объяснением​

Answer 1

1)

$\frac{1}{8} m^{2} +m+2=0$ I×8

$m^{2} +8m+16=0\\D=b^{2} -4ac=8^{2} -4\times1\times16=0\\m_{1,2} =\frac{-b\pm\sqrt{D} }{2a} =\frac{-8}{2} =-4$

2)

$0,5n^{2} -3n+4,5=0$ I×2

$n^{2} -6n+9=0\\D=b^{2}-4ac=(-6)^{2} -4\times1\times9=0\\n_{1,2} =\frac{-b\pm\sqrt{D} }{2a} =\frac{6}{2} =3$

3)

$25x^{2} -20x+4=0\\D=b^{2} -4ac=(-20)^{2} -4\times25\times4=0\\x_{1,2} =\frac{-b\pm\sqrt{D} }{2a} =\frac{20}{50} =\frac{2}{5} =0,4$