# How do you use synthetic substitution to find p(-3) for #p(x)=4x^3-5x^2+7x-10#?

##### 1 Answer

-184

#### Explanation:

Well, you need to know what a synthetic substitution is. I am not going to explain this here but just show you the steps.

I didn't know what it was until I read this question so I googled it and found some great Youtube videos that explain how to do the trick. Here is one, for example

So in this question, we want to find p(-3) so write down

Here are the steps:

- drop down the 4.

- multiply 4 by -3.

- write -12 below the -5.

- add -5 and -12.

- multiply -17 by -3.

- write 51 below the 7.

- add 51 and 7.

- multiply 58 by -3.

- write -174 below the -10.

- add -174 and -10.

i.e.

You can check if this answer is correct by directly substituting in the original equation:

i.e.

That's it. Hope it helped.