Datrys =sqrt{2/5}+3sqrt{5}-4sqrt{5}

$$= \sqrt { \frac { 2 } { 5 } } + 3 \sqrt { 5 } - 4 \sqrt { 5 }$$

Enrhifo

$$\frac{\sqrt{10}}{5}-\sqrt{5}\approx -1.603612445$$

Camau Ateb Byr

Ailysgrifennu ail isradd y rhaniad \sqrt{\frac{2}{5}} fel rhaniad ail israddau \frac{\sqrt{2}}{\sqrt{5}}.

$$\frac{\sqrt{2}}{\sqrt{5}}+3\sqrt{5}-4\sqrt{5}$$

Mae'n rhesymoli enwadur \frac{\sqrt{2}}{\sqrt{5}} drwy luosi'r rhifiadur a'r enwadur â \sqrt{5}.

$$\frac{\sqrt{2}\sqrt{5}}{\left(\sqrt{5}\right)^{2}}+3\sqrt{5}-4\sqrt{5}$$

Sgwâr \sqrt{5} yw 5.

$$\frac{\sqrt{2}\sqrt{5}}{5}+3\sqrt{5}-4\sqrt{5}$$

I luosi \sqrt{2} a \sqrt{5}, dylid lluosi'r rhifau dan yr ail isradd.

$$\frac{\sqrt{10}}{5}+3\sqrt{5}-4\sqrt{5}$$

Cyfuno 3\sqrt{5} a -4\sqrt{5} i gael -\sqrt{5}.

$$\frac{\sqrt{10}}{5}-\sqrt{5}$$

I ychwanegu neu dynnu mynegiannau, rhaid i chi eu ehangu i wneud eu enwaduron yr un fath. Lluoswch \sqrt{5} â \frac{5}{5}.

$$\frac{\sqrt{10}}{5}-\frac{5\sqrt{5}}{5}$$

Gan fod gan \frac{\sqrt{10}}{5} a \frac{5\sqrt{5}}{5} yr un dynodydd, tynnwch nhw drwy dynnu eu rhifiaduron.

$$\frac{\sqrt{10}-5\sqrt{5}}{5}$$