Solve (9x-8)(7x+9)+(-9x-9)(5x-4)-0

$$( 9 x - 8 ) ( 7 x + 9 ) + ( - 9 x - 9 ) ( 5 x - 4 ) - 0$$

Evaluate

$$18x^{2}+16x-36$$

Solution Steps

Apply the distributive property by multiplying each term of 9x-8 by each term of 7x+9.

$$63x^{2}+81x-56x-72+\left(-9x-9\right)\left(5x-4\right)-0$$

Combine 81x and -56x to get 25x.

$$63x^{2}+25x-72+\left(-9x-9\right)\left(5x-4\right)-0$$

Apply the distributive property by multiplying each term of -9x-9 by each term of 5x-4.

$$63x^{2}+25x-72-45x^{2}+36x-45x+36-0$$

Combine 36x and -45x to get -9x.

$$63x^{2}+25x-72-45x^{2}-9x+36-0$$

Combine 63x^{2} and -45x^{2} to get 18x^{2}.

$$18x^{2}+25x-72-9x+36-0$$

Combine 25x and -9x to get 16x.

$$18x^{2}+16x-72+36-0$$

Add -72 and 36 to get -36.

$$18x^{2}+16x-36-0$$

Multiply -1 and 0 to get 0.

$$18x^{2}+16x-36+0$$

Add -36 and 0 to get -36.

$$18x^{2}+16x-36$$

Expand

$$18x^{2}+16x-36$$

Solution Steps

Apply the distributive property by multiplying each term of 9x-8 by each term of 7x+9.

$$63x^{2}+81x-56x-72+\left(-9x-9\right)\left(5x-4\right)-0$$

Combine 81x and -56x to get 25x.

$$63x^{2}+25x-72+\left(-9x-9\right)\left(5x-4\right)-0$$

Apply the distributive property by multiplying each term of -9x-9 by each term of 5x-4.

$$63x^{2}+25x-72-45x^{2}+36x-45x+36-0$$

Combine 36x and -45x to get -9x.

$$63x^{2}+25x-72-45x^{2}-9x+36-0$$

Combine 63x^{2} and -45x^{2} to get 18x^{2}.

$$18x^{2}+25x-72-9x+36-0$$

Combine 25x and -9x to get 16x.

$$18x^{2}+16x-72+36-0$$

Add -72 and 36 to get -36.

$$18x^{2}+16x-36-0$$

Multiply -1 and 0 to get 0.

$$18x^{2}+16x-36+0$$

Add -36 and 0 to get -36.

$$18x^{2}+16x-36$$