Solve 9sqrt{8}+4-9*sqrt{8}-4

$$9 \sqrt { 8 } + 4 - 9 \cdot \sqrt { 8 } - 4$$

Evaluate

$$0$$

Solution Steps

Factor 8=2^{2}\times 2. Rewrite the square root of the product \sqrt{2^{2}\times 2} as the product of square roots \sqrt{2^{2}}\sqrt{2}. Take the square root of 2^{2}.

$$9\times 2\sqrt{2}+4-9\sqrt{8}-4$$

Multiply 9 and 2 to get 18.

$$18\sqrt{2}+4-9\sqrt{8}-4$$

Factor 8=2^{2}\times 2. Rewrite the square root of the product \sqrt{2^{2}\times 2} as the product of square roots \sqrt{2^{2}}\sqrt{2}. Take the square root of 2^{2}.

$$18\sqrt{2}+4-9\times 2\sqrt{2}-4$$

Multiply -9 and 2 to get -18.

$$18\sqrt{2}+4-18\sqrt{2}-4$$

Combine 18\sqrt{2} and -18\sqrt{2} to get 0.

$$4-4$$

Subtract 4 from 4 to get 0.

$$0$$

Factor

$$0$$