Solve 3(frac{7+2sqrt{10}}{3})^2+4*(frac{7+2sqrt{10}}{3})*(frac{7-2sqrt{10}}{3})-3*(frac{7-2sqrt{10}}{3})^2

$$3 ( \frac { 7 + 2 \sqrt { 10 } } { 3 } ) ^ { 2 } + 4 \times ( \frac { 7 + 2 \sqrt { 10 } } { 3 } ) \times ( \frac { 7 - 2 \sqrt { 10 } } { 3 } ) - 3 \times ( \frac { 7 - 2 \sqrt { 10 } } { 3 } ) ^ { 2 }$$

Evaluate

$$\frac{56\sqrt{10}}{3}+4\approx 63.02918299$$

Short Solution Steps

To raise \frac{7+2\sqrt{10}}{3} to a power, raise both numerator and denominator to the power and then divide.

$$3\times \frac{\left(7+2\sqrt{10}\right)^{2}}{3^{2}}+4\times \frac{7+2\sqrt{10}}{3}\times \frac{7-2\sqrt{10}}{3}-3\times \left(\frac{7-2\sqrt{10}}{3}\right)^{2}$$

Express 3\times \frac{\left(7+2\sqrt{10}\right)^{2}}{3^{2}} as a single fraction.

$$\frac{3\left(7+2\sqrt{10}\right)^{2}}{3^{2}}+4\times \frac{7+2\sqrt{10}}{3}\times \frac{7-2\sqrt{10}}{3}-3\times \left(\frac{7-2\sqrt{10}}{3}\right)^{2}$$

Cancel out 3 in both numerator and denominator.

$$\frac{\left(2\sqrt{10}+7\right)^{2}}{3}+4\times \frac{7+2\sqrt{10}}{3}\times \frac{7-2\sqrt{10}}{3}-3\times \left(\frac{7-2\sqrt{10}}{3}\right)^{2}$$

Express 4\times \frac{7+2\sqrt{10}}{3} as a single fraction.

$$\frac{\left(2\sqrt{10}+7\right)^{2}}{3}+\frac{4\left(7+2\sqrt{10}\right)}{3}\times \frac{7-2\sqrt{10}}{3}-3\times \left(\frac{7-2\sqrt{10}}{3}\right)^{2}$$

Multiply \frac{4\left(7+2\sqrt{10}\right)}{3} times \frac{7-2\sqrt{10}}{3} by multiplying numerator times numerator and denominator times denominator.

$$\frac{\left(2\sqrt{10}+7\right)^{2}}{3}+\frac{4\left(7+2\sqrt{10}\right)\left(7-2\sqrt{10}\right)}{3\times 3}-3\times \left(\frac{7-2\sqrt{10}}{3}\right)^{2}$$

To add or subtract expressions, expand them to make their denominators the same. Least common multiple of 3 and 3\times 3 is 3\times 3. Multiply \frac{\left(2\sqrt{10}+7\right)^{2}}{3} times \frac{3}{3}.

$$\frac{3\left(2\sqrt{10}+7\right)^{2}}{3\times 3}+\frac{4\left(7+2\sqrt{10}\right)\left(7-2\sqrt{10}\right)}{3\times 3}-3\times \left(\frac{7-2\sqrt{10}}{3}\right)^{2}$$

Since \frac{3\left(2\sqrt{10}+7\right)^{2}}{3\times 3} and \frac{4\left(7+2\sqrt{10}\right)\left(7-2\sqrt{10}\right)}{3\times 3} have the same denominator, add them by adding their numerators.

$$\frac{3\left(2\sqrt{10}+7\right)^{2}+4\left(7+2\sqrt{10}\right)\left(7-2\sqrt{10}\right)}{3\times 3}-3\times \left(\frac{7-2\sqrt{10}}{3}\right)^{2}$$

To raise \frac{7-2\sqrt{10}}{3} to a power, raise both numerator and denominator to the power and then divide.

$$\frac{3\left(2\sqrt{10}+7\right)^{2}+4\left(7+2\sqrt{10}\right)\left(7-2\sqrt{10}\right)}{3\times 3}-3\times \frac{\left(7-2\sqrt{10}\right)^{2}}{3^{2}}$$

Express 3\times \frac{\left(7-2\sqrt{10}\right)^{2}}{3^{2}} as a single fraction.

$$\frac{3\left(2\sqrt{10}+7\right)^{2}+4\left(7+2\sqrt{10}\right)\left(7-2\sqrt{10}\right)}{3\times 3}-\frac{3\left(7-2\sqrt{10}\right)^{2}}{3^{2}}$$

Cancel out 3 in both numerator and denominator.

$$\frac{3\left(2\sqrt{10}+7\right)^{2}+4\left(7+2\sqrt{10}\right)\left(7-2\sqrt{10}\right)}{3\times 3}-\frac{\left(-2\sqrt{10}+7\right)^{2}}{3}$$

Use binomial theorem \left(a+b\right)^{2}=a^{2}+2ab+b^{2} to expand \left(-2\sqrt{10}+7\right)^{2}.

$$\frac{3\left(2\sqrt{10}+7\right)^{2}+4\left(7+2\sqrt{10}\right)\left(7-2\sqrt{10}\right)}{3\times 3}-\frac{4\left(\sqrt{10}\right)^{2}-28\sqrt{10}+49}{3}$$

The square of \sqrt{10} is 10.

$$\frac{3\left(2\sqrt{10}+7\right)^{2}+4\left(7+2\sqrt{10}\right)\left(7-2\sqrt{10}\right)}{3\times 3}-\frac{4\times 10-28\sqrt{10}+49}{3}$$

Multiply 4 and 10 to get 40.

$$\frac{3\left(2\sqrt{10}+7\right)^{2}+4\left(7+2\sqrt{10}\right)\left(7-2\sqrt{10}\right)}{3\times 3}-\frac{40-28\sqrt{10}+49}{3}$$

Add 40 and 49 to get 89.

$$\frac{3\left(2\sqrt{10}+7\right)^{2}+4\left(7+2\sqrt{10}\right)\left(7-2\sqrt{10}\right)}{3\times 3}-\frac{89-28\sqrt{10}}{3}$$

To add or subtract expressions, expand them to make their denominators the same. Least common multiple of 3\times 3 and 3 is 3\times 3. Multiply \frac{89-28\sqrt{10}}{3} times \frac{3}{3}.

$$\frac{3\left(2\sqrt{10}+7\right)^{2}+4\left(7+2\sqrt{10}\right)\left(7-2\sqrt{10}\right)}{3\times 3}-\frac{3\left(89-28\sqrt{10}\right)}{3\times 3}$$

Since \frac{3\left(2\sqrt{10}+7\right)^{2}+4\left(7+2\sqrt{10}\right)\left(7-2\sqrt{10}\right)}{3\times 3} and \frac{3\left(89-28\sqrt{10}\right)}{3\times 3} have the same denominator, subtract them by subtracting their numerators.

$$\frac{3\left(2\sqrt{10}+7\right)^{2}+4\left(7+2\sqrt{10}\right)\left(7-2\sqrt{10}\right)-3\left(89-28\sqrt{10}\right)}{3\times 3}$$

Use binomial theorem \left(a+b\right)^{2}=a^{2}+2ab+b^{2} to expand \left(2\sqrt{10}+7\right)^{2}.

$$\frac{3\left(4\left(\sqrt{10}\right)^{2}+28\sqrt{10}+49\right)+4\left(7+2\sqrt{10}\right)\left(7-2\sqrt{10}\right)}{3\times 3}-\frac{89-28\sqrt{10}}{3}$$

The square of \sqrt{10} is 10.

$$\frac{3\left(4\times 10+28\sqrt{10}+49\right)+4\left(7+2\sqrt{10}\right)\left(7-2\sqrt{10}\right)}{3\times 3}-\frac{89-28\sqrt{10}}{3}$$

Multiply 4 and 10 to get 40.

$$\frac{3\left(40+28\sqrt{10}+49\right)+4\left(7+2\sqrt{10}\right)\left(7-2\sqrt{10}\right)}{3\times 3}-\frac{89-28\sqrt{10}}{3}$$

Add 40 and 49 to get 89.

$$\frac{3\left(89+28\sqrt{10}\right)+4\left(7+2\sqrt{10}\right)\left(7-2\sqrt{10}\right)}{3\times 3}-\frac{89-28\sqrt{10}}{3}$$

Multiply 3 and 3 to get 9.

$$\frac{3\left(89+28\sqrt{10}\right)+4\left(7+2\sqrt{10}\right)\left(7-2\sqrt{10}\right)}{9}-\frac{89-28\sqrt{10}}{3}$$

To add or subtract expressions, expand them to make their denominators the same. Least common multiple of 9 and 3 is 9. Multiply \frac{89-28\sqrt{10}}{3} times \frac{3}{3}.

$$\frac{3\left(89+28\sqrt{10}\right)+4\left(7+2\sqrt{10}\right)\left(7-2\sqrt{10}\right)}{9}-\frac{3\left(89-28\sqrt{10}\right)}{9}$$

Since \frac{3\left(89+28\sqrt{10}\right)+4\left(7+2\sqrt{10}\right)\left(7-2\sqrt{10}\right)}{9} and \frac{3\left(89-28\sqrt{10}\right)}{9} have the same denominator, subtract them by subtracting their numerators.

$$\frac{3\left(89+28\sqrt{10}\right)+4\left(7+2\sqrt{10}\right)\left(7-2\sqrt{10}\right)-3\left(89-28\sqrt{10}\right)}{9}$$

Do the multiplications in 3\left(89+28\sqrt{10}\right)+4\left(7+2\sqrt{10}\right)\left(7-2\sqrt{10}\right)-3\left(89-28\sqrt{10}\right).

$$\frac{267+84\sqrt{10}+196-56\sqrt{10}+56\sqrt{10}-160-267+84\sqrt{10}}{9}$$

Do the calculations in 267+84\sqrt{10}+196-56\sqrt{10}+56\sqrt{10}-160-267+84\sqrt{10}.

$$\frac{36+168\sqrt{10}}{9}$$

Factor

$$\frac{4 {(14 \sqrt{10} + 3)}}{3} = 63.029182989809755$$