Solve y^3-a=(y-3)(y^2+3y+9)

$$y ^ { 3 } - a = ( y - 3 ) ( y ^ { 2 } + 3 y + 9 )$$

Solve for a

$$a=27$$

Steps for Solving Linear Equation

Use the distributive property to multiply y-3 by y^{2}+3y+9 and combine like terms.

$$y^{3}-a=y^{3}-27$$

Subtract y^{3} from both sides.

$$-a=y^{3}-27-y^{3}$$

Combine y^{3} and -y^{3} to get 0.

$$-a=-27$$

Multiply both sides by -1.

$$a=27$$

Solve for y (complex solution)

$$y\in \mathrm{C}$$

$$a=27$$

Solve for y

$$y\in \mathrm{R}$$

$$a=27$$