# Simplifying Algebraic Expressions

• February 24th 2011, 08:22 PM
Substince
Simplifying Algebraic Expressions
Hey All,

Problem: $a^{3(7-x)}a^x$

I'm not sure what to do with the $a^{3(7-x)}$.

It looks like I could use the distributive law which would make $a^{21-3x}$ but I'm not sure if that applies to exponents.

Thanks,
• February 24th 2011, 08:30 PM
Prove It
$\displaystyle a^{3(7-x)}a^x = a^{3(7-x) + x}$.

Now expand and collect like terms in the power...
• February 24th 2011, 08:39 PM
Substince
Wow I can't believe its that simple and how I missed that Thanks!

so just to verify if you could $a^{3(7-x)}a^x = a^{3(7-x)+x} = a^{(21-3x)+x} = a^{21-2x}$
• February 25th 2011, 03:20 AM
HallsofIvy
Yes, that is correct.