Solve (2x)(-3y)-6y(-2x)+4(-x)(-y)-21xy

$$( 2 x ) ( - 3 y ) - 6 y ( - 2 x ) + 4 ( - x ) ( - y ) - 21 x y$$

Evaluate

$$-11xy$$

Solution Steps

Multiply 2 and -3 to get -6.

$$-6xy-6y\left(-2\right)x+4\left(-x\right)\left(-y\right)-21xy$$

Multiply 6 and -2 to get -12.

$$-6xy-\left(-12yx\right)+4\left(-x\right)\left(-y\right)-21xy$$

The opposite of -12yx is 12yx.

$$-6xy+12yx+4\left(-x\right)\left(-y\right)-21xy$$

Combine -6xy and 12yx to get 6xy.

$$6xy+4\left(-x\right)\left(-y\right)-21xy$$

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

$$-15xy+4\left(-x\right)\left(-y\right)$$

Multiply 4 and -1 to get -4.

$$-15xy-4x\left(-1\right)y$$

Multiply -4 and -1 to get 4.

$$-15xy+4xy$$

Combine -15xy and 4xy to get -11xy.

$$-11xy$$

Differentiate w.r.t. x

$$-11y$$