Factoring??? Help us solve this problem?

Question

Ok, between two of us, we can't figure this problem out. We think it might be a book error, but we wondered if anyone sees something we don't.

(x squared + 3x) - (x squared + 2x +3)

We need to simplify the equation and come up with an answer of x-3. Every way we try to do this comes out wrong.

(Sorry, I don't know how to do square root numbers on the computer.)

Answer 1

you are forgetting to distribute the subtraction into the second parentheses.

(x^2 + 3x) - (x^2 + 2x + 3)
is the same as
(x^2 + 3x) + (-x^2 - 2x - 3)
see how the signs changed? now let's remove the parentheses from the expression.

x^2 + 3x - x^2 - 2x -3

add everything up and you get
(x^2 - x^2) + (3x - 2x) - 3
which is the same as

x - 3

Answer 2

To do power, the sign to use is ^ So a square is ^2

You can simplify by opening up all the bracket before you start to solve. You should know that - * + will give you a - (rules)

(x^2 + 3x) - (x^2+2x+3)
= x^2 + 3x - x^2-2x-3
= x^2 - x^2+ 3x -2x-3
=x-3

Answer 3

(x^2 + 3x) - (x^2 + 2x + 3)

Your first step would be to distribute that minus sign over the second set of brackets.

x^2 + 3x - x^2 - 2x - 3

Combine like terms; notice that there's an x^2 and a -x^2, which will conveniently cancel out. Also, the 3x and -2x will combine to make x. To show this in absolute detail, I'll rearrange the terms and show you.

x^2 - x^2 + 3x - 2x - 3
(x^2 - x^2) + (3x - 2x) - 3
(0) + (x) - 3

x - 3

Answer 4

(x² + 3x) - (x² + 2x + 3)

In subtracting 2 polynomials, subtract those which are like terms. Thus,
= [(x²) - (x²)] + [(3x) - (2x)] + (-3)

Thus,
= 0 + x + (-3)

Therefore,
= x - 3

^_^