Solve (1-2/7)^2+(-1-2/7)^2+(1-2/7)^2

$$( 1 - \frac { 2 } { 7 } ) ^ { 2 } + ( - 1 - \frac { 2 } { 7 } ) ^ { 2 } + ( 1 - \frac { 2 } { 7 } ) ^ { 2 }$$

Evaluate

$$\frac{131}{49}\approx 2.673469388$$

Solution Steps

Subtract \frac{2}{7} from 1 to get \frac{5}{7}.

$$\left(\frac{5}{7}\right)^{2}+\left(-1-\frac{2}{7}\right)^{2}+\left(1-\frac{2}{7}\right)^{2}$$

Calculate \frac{5}{7} to the power of 2 and get \frac{25}{49}.

$$\frac{25}{49}+\left(-1-\frac{2}{7}\right)^{2}+\left(1-\frac{2}{7}\right)^{2}$$

Subtract \frac{2}{7} from -1 to get -\frac{9}{7}.

$$\frac{25}{49}+\left(-\frac{9}{7}\right)^{2}+\left(1-\frac{2}{7}\right)^{2}$$

Calculate -\frac{9}{7} to the power of 2 and get \frac{81}{49}.

$$\frac{25}{49}+\frac{81}{49}+\left(1-\frac{2}{7}\right)^{2}$$

Add \frac{25}{49} and \frac{81}{49} to get \frac{106}{49}.

$$\frac{106}{49}+\left(1-\frac{2}{7}\right)^{2}$$

Subtract \frac{2}{7} from 1 to get \frac{5}{7}.

$$\frac{106}{49}+\left(\frac{5}{7}\right)^{2}$$

Calculate \frac{5}{7} to the power of 2 and get \frac{25}{49}.

$$\frac{106}{49}+\frac{25}{49}$$

Add \frac{106}{49} and \frac{25}{49} to get \frac{131}{49}.

$$\frac{131}{49}$$

Factor

$$\frac{131}{7 ^ {2}} = 2\frac{33}{49} = 2.673469387755102$$