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marcybaby
simplify by factoring. \[\sqrt{90}\] i get 3√10
sqrt90 = sqrt9 * sqrt 10 you are correct
we think of number that go into 90 that give is a 'nice ' square root that we can work out easily with no decimals if possible by 'nice' square roots we mean \[\sqrt{4},\sqrt{9},\sqrt{16},\sqrt{25}.....\] these numbers are called 'square numbers because you can form a square out of 4 dots, 9 dots, 16 dots etc...so \[\sqrt{90}=\sqrt{9}\sqrt{10}=3\sqrt{10}\]