Every question like this I have gotten wrong:

"Multiply or divide the expression below. Leave your answer as simplified as possible."
(3x-1)(x+7) 10(2x-5)
--------- • ---------
4(2x-5) (4x+1)(x+7)

This is from the college preparatory math section 10.1.4

I need to find what the denominator can not equal.

Go to webmath, it's a site on the internet. When you get there click on home and scroll down to complex numbers, multiplying. There you can type in the problem and it will show you step by step how to do this. Your gonna love this site. Take care!

ummm.... its been a while. i think its 10(3x^2)/ 4x

To find the values that the denominator cannot equal, we need to identify the values that would make the denominator equal to zero. In other words, we need to identify the values that would result in an undefined expression.

Looking at the denominator, we have:

(4x+1)(x+7)

To find the values that make the denominator equal to zero, we set each factor equal to zero and solve for x:

4x + 1 = 0
x + 7 = 0

Let's solve each equation separately:

1) For 4x + 1 = 0:

Subtract 1 from both sides:
4x = -1

Divide both sides by 4:
x = -1/4

2) For x + 7 = 0:

Subtract 7 from both sides:
x = -7

So, the values that make the denominator equal to zero are x = -1/4 and x = -7.

Therefore, the denominator cannot equal -1/4 and -7.