Solve -9(4a-5)(4a+5)

$$- 9 ( 4 a - 5 ) ( 4 a + 5 )$$

Evaluate

$$225-144a^{2}$$

Solution Steps

Use the distributive property to multiply -9 by 4a-5.

$$\left(-36a+45\right)\left(4a+5\right)$$

Apply the distributive property by multiplying each term of -36a+45 by each term of 4a+5.

$$-144a^{2}-180a+180a+225$$

Combine -180a and 180a to get 0.

$$-144a^{2}+225$$

Expand

$$225-144a^{2}$$

Solution Steps

Use the distributive property to multiply -9 by 4a-5.

$$\left(-36a+45\right)\left(4a+5\right)$$

Apply the distributive property by multiplying each term of -36a+45 by each term of 4a+5.

$$-144a^{2}-180a+180a+225$$

Combine -180a and 180a to get 0.

$$-144a^{2}+225$$