Discussion about math, puzzles, games and fun. Useful symbols: ÷ × ½ √ ∞ ≠ ≤ ≥ ≈ ⇒ ± ∈ Δ θ ∴ ∑ ∫ π -¹ ² ³ °

You are not logged in.

- Topics: Active | Unanswered

You should use the substitution idea.

That is correct.

Whatever works for you is good.

I never knew you were just behind your machine

I do not understand.

Try the second one and post if you get stuck.

(-3)(1/2) = (-3/2)

Hi;

Can you work the second one?

Hi;

Post #3 is me.

Hi ydnac;

I am getting 10.5 hours just like back then.

Hi;

The book is right in both cases.

This is what I mean √

Normally you would say what number when multiplied by itself equals 9

Well 3 x 3 = 9 and (-3) x (-3) = 9 so why is it not

The reason is the √ operator or instruction means only the positive one so the first one is correct. There is more but it is jargon that you do not need right now.

You are welcome.

Since when we are solving an equation like this we are always trying to get an x all by itself on one side.

We know that 2 x (1/2) = 1 so if we square both sides

we are done.

Please, is the following the same?

x^2 and x^1/2

No , they are not the same. x^2 says x * x while x^(1/2) =√x

For numbers it will be easier to see:

4^2 = 4 x 4 = 16

4^(1/2) = √4 = 2

Very good! Anything else?

Do you see why you raise both sides up to the 3 / 2 power?

Do you mean here?

Hi;

EM:

```
s1 = Permutations[{m, a, t, h, e, m, a, t, i, c, s}, {11}];
Cases[s1, {___, a, ___, e, ___, a, ___, i, ___}] // Length
```

Analytically: