5/8 of 32 is 20
You seemed to have multiplied instead of making them proportional. Easy mistake to make
2 divided by 1/3 equals 6
The original can be rewritten as

. Because i^2 is equal to -1, we can replace the -1 in each radicand with i^2, like this:

. Now, i-squared is a perfect square that can be pulled out of each radicand as a single i.

. 24 has a perfect square hidden in it. 4 * 6 = 24 and 4 is a perfect square. So let's break this up, step by step.

and then

. We will now multiply the i and the 2i, and multiply the square root of 6 times the square root of 6:

. 36 itself is a perfect square because 6 * 6 = 36. So we will do that simplification now.

. Multiplying the 2 and the 6 gives us

. But here we are back to the fact that i-squared is equal to -1, so 2(-1)(6) = -12. See how that works?
The answer is: [A]: " 20a − 5b − 9 " .
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Explanation:
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(12a <span>+ 7b) + (−6a − 9) + (14a − 12b) =
12a </span><span>+ 7b + 1(−6a − 9) + 1(14a − 12b) =
</span>
12a + 7b + (1*-6a) + (1*-9) + (1*14a) + (1* -12b) =
12a + 7b − 6a − 9 + 14a − 12b = ?
Combine the "like terms:
12a − 6a + 14a = 20a ;
7b − 12b = - 5b ;
and then we have "-9" ;
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So, write as: " 20a − 5b − 9 " ; which is: Answer choice: [A].
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