Simplify the square root [tex]7 \sqrt{90} = 7\sqrt{3 { }^{2} \times 10} [/tex] Separate the numbers in the square root to look like this [tex]7 \sqrt{3 ^{2} } \sqrt{10} [/tex] Because three is squared, it cancels out the square root [tex]7 \times 3 \sqrt{10} [/tex] Simplify to get your answer: [tex]21 \sqrt{10} [/tex]
