What is -4 square root of 90 + 2 square root of 160?

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Answer 1 · 2018-04-30T17:20:28

$-4sqrt(10)$

$-4sqrt(90)+ 2sqrt(160) = ?$

Assuming this to be the question(unfortunately, the lack of math symbols makes it ambiguous), the answer shall be:

$= -4(3)sqrt(10) + 2(4)sqrt(10)$
^What I've done here is $sqrt(ab) = sqrt(a)sqrt(b)$ (9 times 10 and 16 times 10 respectively)

$= -12sqrt(10)+ 8sqrt(10)$
$= -4sqrt(10)$

Answer 2 · 2018-04-30T17:26:19

$-4 \sqrt{90} + 2 \sqrt{160}$ $= -12 sqrt{10} + 8 sqrt{10}$ $= -4 sqrt{10}$

$-4 \sqrt{90} + 2 \sqrt{160}$

$-4 \sqrt{3^2 cdot 10 } + 2 \sqrt{4^2 cdot 10}$

$= -12 sqrt{10} + 8 sqrt{10}$

$= -4 sqrt{10}$

Why does it say just asked when it's two years old?

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