Datrys [(5*9^2)-(90+Y^2)]^2

$$[ ( 5 \times 9 ^ { 2 } ) - ( 90 + Y ^ { 2 } ) ] ^ { 2 }$$

Enrhifo

$$\left(315-Y^{2}\right)^{2}$$

Camau Ateb

Cyfrifo 9 i bŵer 2 a chael 81.

$$\left(5\times 81-\left(90+Y^{2}\right)\right)^{2}$$

Lluosi 5 a 81 i gael 405.

$$\left(405-\left(90+Y^{2}\right)\right)^{2}$$

I ddod o hyd i wrthwyneb 90+Y^{2}, dewch o hyd i wrthwyneb pob term.

$$\left(405-90-Y^{2}\right)^{2}$$

Tynnu 90 o 405 i gael 315.

$$\left(315-Y^{2}\right)^{2}$$

Defnyddio'r theorem binomaidd \left(a-b\right)^{2}=a^{2}-2ab+b^{2} i ehangu'r \left(315-Y^{2}\right)^{2}.

$$99225-630Y^{2}+\left(Y^{2}\right)^{2}$$

I godi pŵer rhif i bŵer arall, lluoswch yr esbonyddion. Lluoswch 2 a 2 i gael 4.

$$99225-630Y^{2}+Y^{4}$$

Ehangu

$$Y^{4}-630Y^{2}+99225$$

Camau Ateb

Cyfrifo 9 i bŵer 2 a chael 81.

$$\left(5\times 81-\left(90+Y^{2}\right)\right)^{2}$$

Lluosi 5 a 81 i gael 405.

$$\left(405-\left(90+Y^{2}\right)\right)^{2}$$

I ddod o hyd i wrthwyneb 90+Y^{2}, dewch o hyd i wrthwyneb pob term.

$$\left(405-90-Y^{2}\right)^{2}$$

Tynnu 90 o 405 i gael 315.

$$\left(315-Y^{2}\right)^{2}$$

Defnyddio'r theorem binomaidd \left(a-b\right)^{2}=a^{2}-2ab+b^{2} i ehangu'r \left(315-Y^{2}\right)^{2}.

$$99225-630Y^{2}+\left(Y^{2}\right)^{2}$$

I godi pŵer rhif i bŵer arall, lluoswch yr esbonyddion. Lluoswch 2 a 2 i gael 4.

$$99225-630Y^{2}+Y^{4}$$