Question

Ella simplifies (3b+4r)+ (-2b-r) and says the result is b+ 5r. What error did Ella make?

Answer 1

Ella' s error was adding (4r+r) instead of subtracting (4r-r)

Explanation:

Answer 2

Elsa's error was adding (4r+r) instead of subtracting (4r-r)

Explanation:

we have

`(3b+4r)+ (-2b-r)`

step 1

Eliminate the parenthesis

`3b+4r-2b-r`

step 2

Group terms that contain the same variable

`3b-2b+4r-r`

step 3

Combine like terms

`b+3r`

therefore

Elsa's error was adding (4r+r) instead of subtracting (4r-r)