Solve (x-4)(x+5)+(x-4)(x+5)

$$( x - 4 ) ( x + 5 ) + ( x - 4 ) ( x + 5 )$$

Evaluate

$$2\left(x-4\right)\left(x+5\right)$$

Solution Steps

Apply the distributive property by multiplying each term of x-4 by each term of x+5.

$$x^{2}+5x-4x-20+\left(x-4\right)\left(x+5\right)$$

Combine 5x and -4x to get x.

$$x^{2}+x-20+\left(x-4\right)\left(x+5\right)$$

Apply the distributive property by multiplying each term of x-4 by each term of x+5.

$$x^{2}+x-20+x^{2}+5x-4x-20$$

Combine 5x and -4x to get x.

$$x^{2}+x-20+x^{2}+x-20$$

Combine x^{2} and x^{2} to get 2x^{2}.

$$2x^{2}+x-20+x-20$$

Combine x and x to get 2x.

$$2x^{2}+2x-20-20$$

Subtract 20 from -20 to get -40.

$$2x^{2}+2x-40$$

Expand

$$2x^{2}+2x-40$$

Solution Steps

Apply the distributive property by multiplying each term of x-4 by each term of x+5.

$$x^{2}+5x-4x-20+\left(x-4\right)\left(x+5\right)$$

Combine 5x and -4x to get x.

$$x^{2}+x-20+\left(x-4\right)\left(x+5\right)$$

Apply the distributive property by multiplying each term of x-4 by each term of x+5.

$$x^{2}+x-20+x^{2}+5x-4x-20$$

Combine 5x and -4x to get x.

$$x^{2}+x-20+x^{2}+x-20$$

Combine x^{2} and x^{2} to get 2x^{2}.

$$2x^{2}+x-20+x-20$$

Combine x and x to get 2x.

$$2x^{2}+2x-20-20$$

Subtract 20 from -20 to get -40.

$$2x^{2}+2x-40$$