Solve =2sqrt{18}-sqrt{8}

$$= 2 \sqrt { 18 } - \sqrt { 8 }$$

Evaluate

$$4\sqrt{2}\approx 5.656854249$$

Solution Steps

Factor 18=3^{2}\times 2. Rewrite the square root of the product \sqrt{3^{2}\times 2} as the product of square roots \sqrt{3^{2}}\sqrt{2}. Take the square root of 3^{2}.

$$2\times 3\sqrt{2}-\sqrt{8}$$

Multiply 2 and 3 to get 6.

$$6\sqrt{2}-\sqrt{8}$$

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}.

$$6\sqrt{2}-2\sqrt{2}$$

Combine 6\sqrt{2} and -2\sqrt{2} to get 4\sqrt{2}.

$$4\sqrt{2}$$