1. 7.96(2.4494 - 2)
Malaygoel, it's not that your wrong it's just that the answer needs to be in simplest radical form, otherwise it would've taken maybe 4 seconds to do.

Also,
$\displaystyle \frac{15.92}{2} (\sqrt{ 6} - \sqrt{ 4})= \sqrt{3.99}\sqrt{ 6} - \sqrt{3.99}\sqrt{ 4}$
where did you get $\displaystyle \sqrt{3.99}$?
Remember: $\displaystyle \frac{15.92}{2}=7.96=\sqrt{63.3616}$

2. √23.94 - √15.96 = √7.98/2 = 3.9
You've done two things wrong in your expression. First off if you want to turn 15.92 into a radical number you need to remember this rule:
$\displaystyle x = \sqrt{x^2}$
It doesn't equal this:
$\displaystyle x \neq \sqrt{x} \neq \sqrt{\sqrt{x}}$

and you also subtracted radicals incorrectly, remember these rules:
$\displaystyle \sqrt{6}\pm\sqrt{4} \neq \sqrt{6\pm4}$
$\displaystyle \sqrt{6}\sqrt{4} = \sqrt{6\cdot4}$

I figured it out.
Continuing on my work:

$\displaystyle \left(4\sqrt{6}-8\right)\left(\sqrt{3.9601}\right)$
$\displaystyle 4\sqrt{6}\sqrt{3.9601}-8\sqrt{3.9601}$
$\displaystyle 4\sqrt{6\cdot3.9601}-\sqrt{64}\sqrt{3.9601}$
$\displaystyle 4\sqrt{23.7606}-\sqrt{64\cdot3.9601}$
$\displaystyle 4\sqrt{23.7606}-\sqrt{253.4464}$
$\displaystyle 4\sqrt{4\cdot7.9202}-15.92$
$\displaystyle 4\sqrt{4}\sqrt{7.9202}-15.92$
$\displaystyle 4\cdot2\sqrt{7.9202}-15.92$
$\displaystyle 8\sqrt{7.9202}-15.92 \approx 3.6$

Looking back, I did more work than was needed at the beginning.
(and it seems I have triple posted)

4. ## Wow

Thanks to you both for that information. I stayed on it until about midnight last night and had had enough of that problem. I keep trying no matter if I get the problem wrong but sometimes it easier seeing someone else show where you've gone wrong. Thanks you very much!!

5. ## The 3.99

Quick,

I took the square root of 15.92 to come up with the 3.99 thinking I could do the problem that way. I now know that was a wrong maneuver. Thanks again.

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