# Thread: I need help with these rational expressions

1. ## I need help with these rational expressions

Okay so these are the 4 rational expressions that I need step by step answers on:

1. √(24a^4b^5c^9)

2. 2√(50) + 13√(200)

3. (rewrite the radical expression in simplier radical form) - I have no idea what that means. 3√(5) (5√(3) + 2√(12))

4. (Solve the equation using your knowledge of radicals) - does it mean to just solve the equation? √(x + 12) = x

sorry it's a lot, these are the four I didn't understand.

2. ## take out the squares

is #1 this??

$\displaystyle \sqrt{24a^{4}b^{5}c^{9}}$ is just take the squares out of it

for #2

$\displaystyle 2\sqrt{50} + 13\sqrt{200} \Rightarrow 2\sqrt{25}\sqrt{2} + 13\sqrt{100}\sqrt{2}$

you can probably see the rest of this..

3. Originally Posted by jenbones
Okay so these are the 4 rational expressions that I need step by step answers on:

1. √(24a^4b^5c^9)

2. 2√(50) + 13√(200)

3. (rewrite the radical expression in simplier radical form) - I have no idea what that means. 3√(5) (5√(3) + 2√(12))

4. (Solve the equation using your knowledge of radicals) - does it mean to just solve the equation? √(x + 12) = x

sorry it's a lot, these are the four I didn't understand.
I understand you want step by step answers but this is not a homework service.

The general rule you will apply in questions 1 and 2 is: $\displaystyle \sqrt{a^2b}=|a|\sqrt{b}$

For 3: $\displaystyle \sqrt{a}\cdot\sqrt{b} = \sqrt{ab}$ (for a and b non-negative)

For 4: If you square both sides you will get a quadratic equation. At the end you should make sure $\displaystyle \displaystyle x \ge 0$ and $\displaystyle x + 12 \ge 0$ hold.

4. Originally Posted by bigwave
is #1 this??

$\displaystyle \sqrt{24a^{4}b^{5}c^{9}}$ is just take the squares out of it

for #2

$\displaystyle 2\sqrt{50} + 13\sqrt{200} \Rightarrow 2\sqrt{25}\sqrt{2} + 13\sqrt{100}\sqrt{2}$

you can probably see the rest of this..
yes number one is correct

5. $\displaystyle \sqrt{24{a}^{4}b^{5}c^{9}} \Rightarrow \sqrt{4}\sqrt{6}\sqrt{a^4}\sqrt{b^4}\sqrt{b}\sqrt{ c^8}\sqrt{c} \Rightarrow 2a^{2}b^{2}c^{4}\sqrt{6bc}$

there are other forms of this if you want fractional exponents.

$\displaystyle #2 \sqrt{25}\sqrt{2} + 13\sqrt{100}\sqrt{2} \Rightarrow 10\sqrt{2}+130\sqrt{2} \Rightarrow 140\sqrt{2}$