Solve (a+2)(a+1)-4(a+1)

$$( a + 2 ) ( a + 1 ) - 4 ( a + 1 )$$

Evaluate

$$\left(a-2\right)\left(a+1\right)$$

Solution Steps

Apply the distributive property by multiplying each term of a+2 by each term of a+1.

$$a^{2}+a+2a+2-4\left(a+1\right)$$

Combine a and 2a to get 3a.

$$a^{2}+3a+2-4\left(a+1\right)$$

Use the distributive property to multiply -4 by a+1.

$$a^{2}+3a+2-4a-4$$

Combine 3a and -4a to get -a.

$$a^{2}-a+2-4$$

Subtract 4 from 2 to get -2.

$$a^{2}-a-2$$

Expand

$$a^{2}-a-2$$

Solution Steps

Apply the distributive property by multiplying each term of a+2 by each term of a+1.

$$a^{2}+a+2a+2-4\left(a+1\right)$$

Combine a and 2a to get 3a.

$$a^{2}+3a+2-4\left(a+1\right)$$

Use the distributive property to multiply -4 by a+1.

$$a^{2}+3a+2-4a-4$$

Combine 3a and -4a to get -a.

$$a^{2}-a+2-4$$

Subtract 4 from 2 to get -2.

$$a^{2}-a-2$$