This is a quadratic equation so we run through the steps for solving quadratic equations.

Transpose all terms to one side leaving a zero on the other.

Factor

Set the factors = 0, and solve the resulting equations.

Let x = 5/2. Then the equation becomes

Do the power first

Next multiply

Add the fractions on the left. Note that we have common denominators.

which checks.

Next let x = -4. The equation becomes

Do the power first.

Then multiply.

which checks.