Datrys {l}{-1.25a+b+1.25c=0}{-a+3b=60}{a-3c=24}

$$\left. \begin{array} { l } { - 1.25 a + b + 1.25 c = 0 } \\ { - a + 3 b = 60 } \\ { a - 3 c = 24 } \end{array} \right.$$

Datrys ar gyfer a, b, c

$$a=20$$

$$b = \frac{80}{3} = 26\frac{2}{3} \approx 26.666666667$$

$$c = -\frac{4}{3} = -1\frac{1}{3} \approx -1.333333333$$

Camau Byr wrth Ddefnyddio Amnewid

Datrys -1.25a+b+1.25c=0 ar gyfer b.

$$b=1.25a-1.25c$$

Amnewid 1.25a-1.25c am b yn yr hafaliad -a+3b=60.

$$-a+3\left(1.25a-1.25c\right)=60$$

Datrys yr ail hafaliad ar gyfer a a'r trydydd hafaliad ar gyfer c.

$$a=\frac{15}{11}c+\frac{240}{11} c=\frac{1}{3}a-8$$

Amnewid \frac{15}{11}c+\frac{240}{11} am a yn yr hafaliad c=\frac{1}{3}a-8.

$$c=\frac{1}{3}\left(\frac{15}{11}c+\frac{240}{11}\right)-8$$

Datrys c=\frac{1}{3}\left(\frac{15}{11}c+\frac{240}{11}\right)-8 ar gyfer c.

$$c=-\frac{4}{3}$$

Amnewid -\frac{4}{3} am c yn yr hafaliad a=\frac{15}{11}c+\frac{240}{11}.

$$a=\frac{15}{11}\left(-\frac{4}{3}\right)+\frac{240}{11}$$

Cyfrifo a o a=\frac{15}{11}\left(-\frac{4}{3}\right)+\frac{240}{11}.

$$a=20$$

Amnewid 20 am a a -\frac{4}{3} am c yn yr hafaliad b=1.25a-1.25c.

$$b=1.25\times 20-1.25\left(-\frac{4}{3}\right)$$

Cyfrifo b o b=1.25\times 20-1.25\left(-\frac{4}{3}\right).

$$b=\frac{80}{3}$$

Mae’r system wedi’i datrys nawr.

$$a=20 b=\frac{80}{3} c=-\frac{4}{3}$$