#### 1. Check whether the following are quadratic equations:

#### (i) (x+1)^{2}=2(x–3)

#### (ii) x^{2}–2x=(–2)(3–x)

#### (iii) (x–2)(x+1)=(x–1)(x+3)

#### (iv) (x–3)(2x+1)=x(x+5)

#### (v) (2x–1)(x–3)=(x+5)(x–1)

#### (vi) x^{2}+3x+1=(x–2)^{2}

#### (vii) (x+2)^{3}=2x(x^{2}–1)

#### (viii) x^{3}–4x^{2}–x+1=(x–2)^{3}