# Thread: Sat II math help

1. ## Sat II math help

√(10)√(2)/
√(15) =?

If a ≠ -b, then a-b/a+b =?

what is the reciprocal of a/b+b/a?

x/yz divided by (y) =?

thanks!

2. Originally Posted by original501
√(10)√(2)/
√(15) =?

If a ≠ -b, then a-b/a+b =?

what is the reciprocal of a/b+b/a?

x/yz divided by (y) =?

thanks!

1. Note and use the following rules

$\displaystyle \sqrt{a} \sqrt{b} = \sqrt{ab}$
$\displaystyle \sqrt{a^2b} = a \sqrt{b}$

2. This cannot be simplified further. a does not equal b because if it did there would be division by 0

3. The reciprocal of x is 1/x. In other words flip the fraction.

You could say $\displaystyle \frac{1}{\frac{a}{b}+\frac{b}{a}}$ but that's crude and it would be better to get a single denominator first

4. When dividing by a whole number/variable multiply the denominator by the value:

$\displaystyle \frac{1}{a} \div b = \frac{1}{ab}$