Jsur07
Hi all -
So I'm a bit stuck with a relatively simple question. If the base of the two numbers is the same, but the variable exponent is different, what is the process to simply the equation?
For example: \(3^x+3\)^x+1
Obviously no hard and fast rules when it comes to addition and exponents, but any help would be appreciated.
Dear
Jsur07,
I'm happy to respond.
This is not so much a "law of exponents" as a trick that involves some number sense.
You no doubt are familiar with the Distributive Law:
A*(B + C) = A*B + A*CTechnically, when we go from left to right in that equation, we are "distributing," and when we go from right to left, we are "factoring out."
We have to apply the factoring out process to the sum or difference of two different powers of the same base.
For example
\(3^x + 3^{x+1} = 1*(3^x) + 3*(3^x) = (1 + 3)*(3^x) = 4*(3^x)\)
We can use this trick even if the exponents are numbers instead of variables.
\(7^{30} + 7^{32} = 1*(7^{30}) + (7^2)*(7^{30}) = (1 + 49)*(7^{30}) = 50*(7^{30})\)
See this blog for more discussion of this technique:
Challenging GMAT Problems with Exponents and RootsDoes all this make sense?
Mike