Need help fast!!

I have a review packet due tommorrow that is worth a ton of points. There are still a few problems i cant find in my book and need your help!!

1. Solve the following inequality. List critical values.
x(x-3)<4
Are the end points of the interval included in the solution set??? Yes/no

2.Solve the following inequality. List critical values.
x^3-6x^2-40x<0

Are the end points of the interval included in the solution set? Yes/no

3. Write the expression in the standard form a-bi. Simplify.
8-i
----
5+i

Thanks in advance guys.

FrustratedMathMan said:

1. Solve the following inequality. List critical values.
x(x-3)<4
Are the end points of the interval included in the solution set??? Yes/no

Click to expand...

Change to x^2 - 3x - 4 < 0, then factor (x-4)(x+1) < 0. Critical points are now staring at you.

2.Solve the following inequality. List critical values.
x^3-6x^2-40x<0
Are the end points of the interval included in the solution set? Yes/no

Click to expand...

Factor x(x^2-6x-40) < 0 Then x(x-10)(x+4) < 0. Again, the critical values are glaring.

3. Write the expression in the standard form a-bi. Simplify.

Code:

   8-i
   ---
   5+i

Multiply Numerator and Denominator by 5-i and simplify. Why are you struggling with this one? It can't be the only one like it in the problem set.

Thanks in advance guys.

Click to expand...

who can solve this first -(x+6)+7x=7x-10

=4