Solve (5)(-b-4a^2)(b-4a^2)

$$( 5 ) ( - b - 4 a ^ { 2 } ) ( b - 4 a ^ { 2 } )$$

Evaluate

$$80a^{4}-5b^{2}$$

Solution Steps

Use the distributive property to multiply 5 by -b-4a^{2}.

$$\left(5\left(-b\right)-20a^{2}\right)\left(b-4a^{2}\right)$$

Use the distributive property to multiply 5\left(-b\right)-20a^{2} by b-4a^{2}.

$$5\left(-b\right)b-20\left(-b\right)a^{2}-20a^{2}b+80a^{4}$$

Multiply -20 and -1 to get 20.

$$5\left(-b\right)b+20ba^{2}-20a^{2}b+80a^{4}$$

Combine 20ba^{2} and -20a^{2}b to get 0.

$$5\left(-b\right)b+80a^{4}$$

Multiply 5 and -1 to get -5.

$$-5bb+80a^{4}$$

Multiply b and b to get b^{2}.

$$-5b^{2}+80a^{4}$$

Expand

$$80a^{4}-5b^{2}$$

Solution Steps

Use the distributive property to multiply 5 by -b-4a^{2}.

$$\left(5\left(-b\right)-20a^{2}\right)\left(b-4a^{2}\right)$$

Use the distributive property to multiply 5\left(-b\right)-20a^{2} by b-4a^{2}.

$$5\left(-b\right)b-20\left(-b\right)a^{2}-20a^{2}b+80a^{4}$$

Multiply -20 and -1 to get 20.

$$5\left(-b\right)b+20ba^{2}-20a^{2}b+80a^{4}$$

Combine 20ba^{2} and -20a^{2}b to get 0.

$$5\left(-b\right)b+80a^{4}$$

Multiply 5 and -1 to get -5.

$$-5bb+80a^{4}$$

Multiply b and b to get b^{2}.

$$-5b^{2}+80a^{4}$$