Help with algebra

[Mathdabbler]

Hello, I’m new here - hope I’m posting the right place.

Here is my problem below. Basically I cannot get to the correct answer that is given as a(a+6). I seem to be ok with the other exercises in the book though. Any help in stepping me through the solution would be greatly appreciated.

 

[Deleted member 4993]

Hello, I’m new here - hope I’m posting the right place.

Here is my problem below. Basically I cannot get to the correct answer that is given as a(a+6). I seem to be ok with the other exercises in the book though. Any help in stepping me through the solution would be greatly appreciated.

View attachment 13547

First - you are correct upto this point! You just have to continue a bit more...

(a+1)² + 4(a+1) - 5 = a² + 2a + 1 + 4a + 4 - 5 = a² + 6a = a * (a + 6)

You just took long - very long and looping route (but not wrong) - route to get there.

The way I would have done: - replace 'x' by '(a+1)' and get

f(a + 1) = [(a + 1) - 1] * [(a + 1) + 5] = [a] * [a + 6]

However, you have "shown" your work nicely!

 

[Mathdabbler]

Aah - got it thank you very much!