Помогите решить уравнения :

a) / sqrt{2x+3} = x

b) / sqrt{2 x^{2} - x-6} = x

А) √ (2x+3) = x; ⇒2x+3≥0; ⇒2x≥-3; ⇒x≥-3/2;

(√ (2x+3)) ²=x²; ⇒

2x+3-x²=0;

x²-2x-3=0;

x₁,₂=1⁺₋√ (1+3) = 1⁺₋2;

x₁=3; ⇒3>-3/2;

x₂=-1; ⇒-1>-3/2;

б) √ (2x²-x-6) = x; ⇒2x²-x-6≥0;

2x²-x-6=0

x₁,₂ = (1⁺₋√ (1+4·2·6)) / 4 = (1⁺₋7) / 4;

x₁ = (1+7) / 4=2;

x₂ = (1-7) / 4=-1.5⇒

x∈ (-∞; -1.5]; x∈[2; +∞)

(√ (2x²-x-6)) ²=x²

2x²-x-6-x²=0;

x²-x-6=0

x₁,₂=1/2⁺₋√ (1/4+6) = 1/2⁺₋√ (25/4) = 1/2⁺₋5/2

x₁=1/2+5/2=3; ⇒2<3<∞;

x₂=1/2-5/2=-2; ⇒-∞<-2<-1.5