Thread: An algebra question

Question: Simplify the following expression.

(2x5^n)^2 + 25^n

this whole equation is divided by

5^n



Answer; 5^n+1


Remarks: I have tried doing this question twice but both attempts were unsuccesful. Please help.

Originally Posted by econlover

Question: Simplify the following expression.

(2x5^n)^2 + 25^n

this whole equation is divided by

5^n



Answer; 5^n+1


Remarks: I have tried doing this question twice but both attempts were unsuccesful. Please help.

1. Use the laws of powers:

Thanks.

I understand most of it but how did you move along from the 1st step of your answer to the second one

that is, in specific terms, where did the 4 go?

considering the numerator (top of fraction) only:

Thanks for the message. But I guess you misinterpret the sign of this "."

It is not 4.5 (4 decimal 5) but 4 . 5 meaning 4 x 5 = 4 times 5

Hope this clears up the misconception

Still don't understand this step. Where did the 1 come from ? What about the positive sign?

Can someone explain? Thanks!

it is only factorising. i was not interpreting your dot as a decimal.

in general:
4x + x = (4+1)x = 5x


You have
=

Which says: "4 lots of plus 1 lot of " equals "5 lots of "

Originally Posted by econlover

Question: Simplify the following expression.

(2x5^n)^2 + 25^n

this whole equation is divided by

5^n



Answer; 5^n+1


Remarks: I have tried doing this question twice but both attempts were unsuccesful. Please help.

Hi ecolover,
answer is correct 5^n+1

follow exp rules carefully. the 4 disappears naturally because 4+1 =5 You should get it from this clue

bjh