Subtract from both sides of the equation.

Subtract from both sides of the equation.

Divide each term in by .

Simplify .

Dividing two negative values results in a positive value.

Cancel the common factor of .

Cancel the common factor.

Divide by .

Simplify each term.

Dividing two negative values results in a positive value.

Cancel the common factor of and .

Factor out of .

Cancel the common factors.

Raise to the power of .

Factor out of .

Cancel the common factor.

Rewrite the expression.

Divide by .

Dividing two negative values results in a positive value.

To rewrite as a function of , write the equation so that is by itself on one side of the equal sign and an expression involving only is on the other side.

Write as a Function of x x^2-kx+21=0