IQ scores are normally distributed with a mean of 100 and a standard deviation of 15. Out of a randomly selected 3100 people from the population, how many of them
would have an IQ less than 133, to the nearest whole number?

When you see an equation with parenthesis around it, you can use this:

Parenthesis

Exponents

Multiplication

Division

Addition

Subtraction

Otherwise known as PEMDAS.

We can see that in the equation, there are parenthesis, so we can open those. We open parenthesis by taking the number right next to the parenthesis (or outside the parenthesis) and we multiply that number by everything inside. So this is what it would look like:

-2x^2 - 10x + 8

See how the signs changed? This rule only applies when you multiply something, but here is how I think of it:

+ and + always equals +.

- and - always equals +.

- and + always equals -.

+ and - always equals -.

So that's it! Just to be clear, the answer is:

-2x^2 - 10x + 8

Hope I helped, sorry if I'm wrong!

`Mschmindy