Solve y=-0.9(x+3)(x-3)

$$y = - 0.9 ( x + 3 ) ( x - 3 )$$

Solve for y

$$y=\frac{81-9x^{2}}{10}$$

Solution Steps

Use the distributive property to multiply -0.9 by x+3.

$$y=\left(-0.9x-2.7\right)\left(x-3\right)$$

Use the distributive property to multiply -0.9x-2.7 by x-3 and combine like terms.

$$y=-0.9x^{2}+8.1$$

Solve for x (complex solution)

$$x=-\sqrt{-\frac{10y}{9}+9}$$

$$x=\sqrt{-\frac{10y}{9}+9}$$

Solve for x

$$x=\frac{\sqrt{81-10y}}{3}$$

$$x=-\frac{\sqrt{81-10y}}{3}\text{, }y\leq \frac{81}{10}$$