Question

помогите с 1 и 4................

Answer 1

1)
$x^{2} =0,6;$
$x^{2} - 0,6=0$
$(x - 0,6)(x + 0,6)=0;$
$x_{1} = 0,6;$
$x_{2} = -0,6;$
2)
$a^{2} + 2b = (3 - 2 sqrt{5})^2 - 2 sqrt{5} = 9 - 12 sqrt{5} + 20 - 2 sqrt{5} = 29 + 14 sqrt{5}$