is the following equation quadratic?
$x^2+2x+11=0$

Find which of the following equations are quadratic:
$(\mathbf{x}-1{)}^2+(\mathbf{x}+2{)}^2+3(\mathbf{x}+1)=0$

Find which of the following equations are quadratic:
$(3x-1{)}^2=5(x+8)$

Check whether the following are quadratic equations:
$2x^2-3\sqrt{x}+5=0$

is the following equation quadratic?
$x^2-2x+5=x^2$

Test, whether the following equation is quadratic equation.
$x+\frac{1}{x}+x^2,x\ne 0$

Check whether the following are quadratic equations:
$(x+1)(x-1)=(x+2)(x+3)$

Check whether the following are quadratic equations:
$(x+2{)}^3=x^3-4$

Find which of the following equations are quadratic:
$x^2+5x-5=(x-3{)}^2$

Find which of the following equations are quadratic:
$5x^2-8x=-3(7-2x)$