Answer:
[tex] 3 \sqrt{2} [/tex]
Step-by-step explanation:
[tex] -3 \sqrt{2} + 3 \sqrt{8} = [/tex]
To add or subtract square roots, you must be taking the square roots of the same number. We need to change square root of 8 into a number times square root of 2.
[tex] = -3 \sqrt{2} + 3 \sqrt{4 \times 2} [/tex]
[tex] = -3 \sqrt{2} + 3\sqrt{4} \times \sqrt{2} [/tex]
[tex] = -3 \sqrt{2} + 3 \times 2 \times \sqrt{2} [/tex]
[tex] = -3 \sqrt{2} + 6 \sqrt{2} [/tex]
Now that we have two square roots of 2, we add them like we add like terms.
[tex] = 3 \sqrt{2} [/tex]
