Datrys f(-3)=(-3)^3-2(-3)/(-3)^2-4

$$f ( - 3 ) = \frac { ( - 3 ) ^ { 3 } - 2 ( - 3 ) } { ( - 3 ) ^ { 2 } - 4 }$$

Enrhifo

$$-\frac{21}{5}=-4.2$$

Camau Ateb

Cyfrifo -3 i bŵer 3 a chael -27.

$$\frac{-27-2\left(-3\right)}{\left(-3\right)^{2}-4}$$

Lluosi 2 a -3 i gael -6.

$$\frac{-27-\left(-6\right)}{\left(-3\right)^{2}-4}$$

Gwrthwyneb -6 yw 6.

$$\frac{-27+6}{\left(-3\right)^{2}-4}$$

Adio -27 a 6 i gael -21.

$$\frac{-21}{\left(-3\right)^{2}-4}$$

Cyfrifo -3 i bŵer 2 a chael 9.

$$\frac{-21}{9-4}$$

Tynnu 4 o 9 i gael 5.

$$\frac{-21}{5}$$

Gellir ailysgrifennu \frac{-21}{5} fel -\frac{21}{5} drwy echdynnu’r arwydd negatif.

$$-\frac{21}{5}$$

Ffactor

$$-\frac{21}{5} = -4\frac{1}{5} = -4.2$$