Solve (5x-7)(3x+3)-(5x-1)(3x+3)

$$( 5 x - 7 ) ( 3 x + 3 ) - ( 5 x - 1 ) ( 3 x + 3 )$$

Evaluate

$$-18x-18$$

Solution Steps

Apply the distributive property by multiplying each term of 5x-7 by each term of 3x+3.

$$15x^{2}+15x-21x-21-\left(5x-1\right)\left(3x+3\right)$$

Combine 15x and -21x to get -6x.

$$15x^{2}-6x-21-\left(5x-1\right)\left(3x+3\right)$$

Apply the distributive property by multiplying each term of 5x-1 by each term of 3x+3.

$$15x^{2}-6x-21-\left(15x^{2}+15x-3x-3\right)$$

Combine 15x and -3x to get 12x.

$$15x^{2}-6x-21-\left(15x^{2}+12x-3\right)$$

To find the opposite of 15x^{2}+12x-3, find the opposite of each term.

$$15x^{2}-6x-21-15x^{2}-12x-\left(-3\right)$$

The opposite of -3 is 3.

$$15x^{2}-6x-21-15x^{2}-12x+3$$

Combine 15x^{2} and -15x^{2} to get 0.

$$-6x-21-12x+3$$

Combine -6x and -12x to get -18x.

$$-18x-21+3$$

Add -21 and 3 to get -18.

$$-18x-18$$

Expand

$$-18x-18$$

Solution Steps

Apply the distributive property by multiplying each term of 5x-7 by each term of 3x+3.

$$15x^{2}+15x-21x-21-\left(5x-1\right)\left(3x+3\right)$$

Combine 15x and -21x to get -6x.

$$15x^{2}-6x-21-\left(5x-1\right)\left(3x+3\right)$$

Apply the distributive property by multiplying each term of 5x-1 by each term of 3x+3.

$$15x^{2}-6x-21-\left(15x^{2}+15x-3x-3\right)$$

Combine 15x and -3x to get 12x.

$$15x^{2}-6x-21-\left(15x^{2}+12x-3\right)$$

To find the opposite of 15x^{2}+12x-3, find the opposite of each term.

$$15x^{2}-6x-21-15x^{2}-12x-\left(-3\right)$$

The opposite of -3 is 3.

$$15x^{2}-6x-21-15x^{2}-12x+3$$

Combine 15x^{2} and -15x^{2} to get 0.

$$-6x-21-12x+3$$

Combine -6x and -12x to get -18x.

$$-18x-21+3$$

Add -21 and 3 to get -18.

$$-18x-18$$