Question

cum se scrie deva la o ecuatie de sub radical de ex.....
$\sqrt{2x+3}=x$
$\sqrt{2x-4}=0$

Answer 1

a)$\sqrt{2x+3} =x;( \sqrt{2x+3} ) ^{2} =x ^{2} ;2x+3= x^{2}$
x²-2x-3=0
Δ=4+12
Δ=16
√Δ=4
x₁=(2+4)/2=3
x₂=(2-4)/2=(-1)

b)$\sqrt{2x-4} =0;( \sqrt{2x-4} ) ^{2} =0 ^{2} ;2x-4=0;2x=4;x=2$