Question

Nakim simplified 3 times the square root of 2x plus x times the square root of 8x minus 5 times the square root of 18x and got -10x times the square root of 2x for an answer.

Part 1: Using complete sentences, explain what Nakim did wrong.

Part 2: Show all your work to simplify the expression.

I dont understand this one at all! please help

Answer 1

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http://openstudy.com/updates/4fc653d5e4b022f1e12dcb0f

Answer 2

\[\sqrt {a^2b}=a\sqrt {b}\]
\[5\sqrt {18x}=5\sqrt {9\times 2x}=5(3\sqrt {2x})=15\sqrt {2x}\]

\[x\sqrt {8x}=x\sqrt {4\times 2x}=2x\sqrt {2x}\]
so
\[3\sqrt {2x}+x\sqrt{2x}-5\sqrt {18x}\]
\[=3\sqrt {2x}+2x\sqrt {2x}-15\sqrt {2x}\]
\[=(3-15+2x)\sqrt {2x}\]
\[=(-12+2x)\sqrt{2x}\]

Answer 3

there was a small typing error.....