Move to the left side of the equation by subtracting it from both sides.

Move to the left side of the equation by subtracting it from both sides.

Use the quadratic formula to find the solutions.

Substitute the values , , and into the quadratic formula and solve for .

Simplify the numerator.

Raise to the power of .

Apply the distributive property.

Multiply by .

Multiply by .

Apply the distributive property.

Multiply by .

Multiply by .

Add and .

Multiply by .

The final answer is the combination of both solutions.

Solve for d 4d^2-5d=21+y