x+x^2/2+2x^2-x

[PinkGlasses]

Hello,

I have this problem I have to solve by combining like terms. It is x+x^2/2+2x^2-x. I know the answer is 5x^2/2, but I don't know the right steps to get that answers. Here's what I did

x+x²/2+2x²-x
=x²/2+2x²+x-x
=x²/2+2x²
=3x²/2

I know that answer is wrong, but I can't figure out how to get the right answer.

 

[pka]

Hello,

I have this problem I have to solve by combining like terms. It is x+x^2/2+2x^2-x. I know the answer is 5x^2/2, but I don't know the right steps to get that answers. Here's what I did

x+x²/2+2x²-x
=x²/2+2x²+x-x
=x²/2+2x²
=3x²/2

I know that answer is wrong, but I can't figure out how to get the right answer.

Why do you thing that answer is wrong?

 

[srmichael]

Hello,

I have this problem I have to solve by combining like terms. It is x+x^2/2+2x^2-x. I know the answer is 5x^2/2, but I don't know the right steps to get that answers. Here's what I did

x+x²/2+2x²-x
=x²/2+2x²+x-x
=x²/2+2x²
=3x²/2

I know that answer is wrong, but I can't figure out how to get the right answer.

In your 3rd line you have \(\displaystyle \frac{x^2}{2}+2x^2\). You can't just add these. You need to find a common denominator.

What is the common denominator? How do you go about adjusting the terms to account for that? If you can understand how, say, \(\displaystyle \frac{1}{2}+3=\frac{7}{2}\) then you be able to apply the same logic to your problem? Make sense?

 

[PinkGlasses]

Thank you srmichael. I forgot about finding a common denominator when adding fractions and whole numbers. XD