Datrys 9sqrt{3}(sqrt{7}-sqrt{15})

$$9 \sqrt { 3 } ( \sqrt { 7 } - \sqrt { 15 } )$$

Enrhifo

$$9\left(\sqrt{21}-3\sqrt{5}\right)\approx -19.130654138$$

Camau Ateb

Defnyddio’r briodwedd ddosbarthu i luosi 9\sqrt{3} â \sqrt{7}-\sqrt{15}.

$$9\sqrt{3}\sqrt{7}-9\sqrt{3}\sqrt{15}$$

I luosi \sqrt{3} a \sqrt{7}, dylid lluosi'r rhifau dan yr ail isradd.

$$9\sqrt{21}-9\sqrt{3}\sqrt{15}$$

Ffactora 15=3\times 5. Ailysgrifennu ail isradd y lluoswm \sqrt{3\times 5} fel lluoswm ail israddau \sqrt{3}\sqrt{5}.

$$9\sqrt{21}-9\sqrt{3}\sqrt{3}\sqrt{5}$$

Lluosi \sqrt{3} a \sqrt{3} i gael 3.

$$9\sqrt{21}-9\times 3\sqrt{5}$$

Lluosi -9 a 3 i gael -27.

$$9\sqrt{21}-27\sqrt{5}$$