Question

I'm supposed to find the value of x, can someone check my work? (I'll post it in the comments)

Answer 1

x(x+1) = x^2+x

Answer 2

@Directrix help

Answer 3

This answer is not correct. I see where the algebra error happened. Just a second.

Answer 4

Ok thank you. I knew something wasn't right but I'm not sure what

Answer 5

I marked the first error. See attachment.

Answer 6

The first line of work is the quantity (x + 5) times the quantity (x -2).
On the right side, x times the quantity (x+1) = x² + 1*x

x times x = x²

2 * x = 2x

Answer 7

So (x + 5)(x - 2) = x (x + 1)
x^2 - 2x + 5x - 10 = x^2 + x
x^2 + 7x - 10 = x^2 + x

Answer 8

Take a second look at this: - 2x + 5x --> The sum is not 7x but what?

Answer 9

Oh okay its 3x. Sorry I wasn't paying attention
It would be:
x^2 + 3x - 10 = x^2 + x

Answer 10

Good.

What is the next step?

Answer 11

Okay...now I need to get x by itself?

Answer 12

Subtract the x^2 terms off both sides first.

Answer 13

x^2 + 3x - 10 = x^2 + x
-x^2 -x^2
-----------------------------
3x - 10 = x

If you agree with that, you can collect the x terms on one side now.

Answer 14

So I would subtract 3x from both sides and get:
-10 = -2x

Answer 15

Correct.

Answer 16

Last step: solve for x.

Answer 17

Add 2 to -10 and get
-8 = x

Answer 18

That is not a 2. It is -2x.

Answer 19

-10 = -2x

You can divide by sides by -2 to solve for x.

Answer 20

But the options given to me are 2.5, 5, 7.5, and 10
Also I see where I made my mistake.

Answer 21

Divide by -2 because we are looking for x, not -2x.

Answer 22

The answer would be 5 correct?

Answer 23

We are not at the answer stage. Solve for x.

Answer 24

x = 5, correct.

Answer 25

Thank you so much. As you can probably see, I'm not very good at math.

Answer 26

Your skills are better than most users here. So, keep working.

Answer 27

I will thank you ^-^

Answer 28

You are welcome.