Datrys (2x+3y)(x-3y)-(2x+y)(x-9y)

$$( 2 x + 3 y ) ( x - 3 y ) - ( 2 x + y ) ( x - 9 y )$$

Enrhifo

$$14xy$$

Camau Ateb

Cyfrifwch y briodoledd ddosrannol drwy luosi pob 2x+3y gan bob x-3y.

$$2x^{2}-6xy+3yx-9y^{2}-\left(2x+y\right)\left(x-9y\right)$$

Cyfuno -6xy a 3yx i gael -3xy.

$$2x^{2}-3xy-9y^{2}-\left(2x+y\right)\left(x-9y\right)$$

Cyfrifwch y briodoledd ddosrannol drwy luosi pob 2x+y gan bob x-9y.

$$2x^{2}-3xy-9y^{2}-\left(2x^{2}-18xy+yx-9y^{2}\right)$$

Cyfuno -18xy a yx i gael -17xy.

$$2x^{2}-3xy-9y^{2}-\left(2x^{2}-17xy-9y^{2}\right)$$

I ddod o hyd i wrthwyneb 2x^{2}-17xy-9y^{2}, dewch o hyd i wrthwyneb pob term.

$$2x^{2}-3xy-9y^{2}-2x^{2}-\left(-17xy\right)-\left(-9y^{2}\right)$$

Gwrthwyneb -17xy yw 17xy.

$$2x^{2}-3xy-9y^{2}-2x^{2}+17xy-\left(-9y^{2}\right)$$

Gwrthwyneb -9y^{2} yw 9y^{2}.

$$2x^{2}-3xy-9y^{2}-2x^{2}+17xy+9y^{2}$$

Cyfuno 2x^{2} a -2x^{2} i gael 0.

$$-3xy-9y^{2}+17xy+9y^{2}$$

Cyfuno -3xy a 17xy i gael 14xy.

$$14xy-9y^{2}+9y^{2}$$

Cyfuno -9y^{2} a 9y^{2} i gael 0.

$$14xy$$

Ehangu

$$14xy$$

Camau Ateb

Cyfrifwch y briodoledd ddosrannol drwy luosi pob 2x+3y gan bob x-3y.

$$2x^{2}-6xy+3yx-9y^{2}-\left(2x+y\right)\left(x-9y\right)$$

Cyfuno -6xy a 3yx i gael -3xy.

$$2x^{2}-3xy-9y^{2}-\left(2x+y\right)\left(x-9y\right)$$

Cyfrifwch y briodoledd ddosrannol drwy luosi pob 2x+y gan bob x-9y.

$$2x^{2}-3xy-9y^{2}-\left(2x^{2}-18xy+yx-9y^{2}\right)$$

Cyfuno -18xy a yx i gael -17xy.

$$2x^{2}-3xy-9y^{2}-\left(2x^{2}-17xy-9y^{2}\right)$$

I ddod o hyd i wrthwyneb 2x^{2}-17xy-9y^{2}, dewch o hyd i wrthwyneb pob term.

$$2x^{2}-3xy-9y^{2}-2x^{2}-\left(-17xy\right)-\left(-9y^{2}\right)$$

Gwrthwyneb -17xy yw 17xy.

$$2x^{2}-3xy-9y^{2}-2x^{2}+17xy-\left(-9y^{2}\right)$$

Gwrthwyneb -9y^{2} yw 9y^{2}.

$$2x^{2}-3xy-9y^{2}-2x^{2}+17xy+9y^{2}$$

Cyfuno 2x^{2} a -2x^{2} i gael 0.

$$-3xy-9y^{2}+17xy+9y^{2}$$

Cyfuno -3xy a 17xy i gael 14xy.

$$14xy-9y^{2}+9y^{2}$$

Cyfuno -9y^{2} a 9y^{2} i gael 0.

$$14xy$$