Question

Kendall says the sum of

(6x2 4xy 2y2) and (4x2 – 2xy – 3y2) is (10x2 2xy – 5y2).

What error did Kendall make?

Answer 1

He combined the like terms 2y2 and –3y2 incorrectly.

Answer 2

Kendall combine like terms
`2y^2` and
`-3y^2` incorrectly.

Explanation:

It is given that Kendall says the sum of
`6x^2+4xy+2y^2` and
`4x^2-2xy-3y^2` is
`10x^2+2xy-5y^2`.

Step 1: Add both expression

`6x^2+4xy+2y^2+4x^2-2xy-3y^2`

Step 2: Combine like terms

`(6x^2+4x^2)+(4xy-2xy)+(2y^2-3y^2)`

Step 3: Simplify

`10x^2+2xy-y^2`

The sum of both expressions is
`10x^2+2xy-y^2`.

Kendall made an error during step 3. His mistake is

`2y^2-3y^2=-5y^2`

Therefore, Kendall combine like terms
`2y^2` and
`-3y^2` incorrectly.