Solve -4sqrt{2}+9sqrt{8}

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

Evaluate

$$14\sqrt{2}\approx 19.798989873$$

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}.

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

Multiply 9 and 2 to get 18.

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

Combine -4\sqrt{2} and 18\sqrt{2} to get 14\sqrt{2}.

$$14\sqrt{2}$$