# Solving a System?

• Feb 4th 2009, 11:06 PM
Solving a System?
Hey Guys!
This is my last question of the Unit that I am planning to send in tomorrow morning.

My text does not provide me with enough examples or information to help me solve this question so I'm looking for some answers please!

Solve the following system:
2^(x+3y) =128 and 2^(3x-7)=2

(Surprised)

Thank You for any help anyone can provide to me!
• Feb 4th 2009, 11:12 PM
red_dog
$\left\{\begin{array}{ll}2^{x+3y}=2^7\\2^{3x-7}=2^1\end{array}\right.\Rightarrow\left\{\begin{a rray}{ll}x+3y=7\\3x-7=1\end{array}\right.$

Now you have yo solve the last system.
• Feb 4th 2009, 11:37 PM

That is actually as far as I got....
• Feb 5th 2009, 04:41 AM
Jester
Quote:

Originally Posted by red_dog
$\left\{\begin{array}{ll}2^{x+3y}=2^7\\2^{3x-7}=2^1\end{array}\right.\Rightarrow\left\{\begin{a rray}{ll}x+3y=7\\3x-7=1\end{array}\right.$

Now you have yo solve the last system.

Quote:

That is actually as far as I got....

From red-dog's work, solve the second for x

$x = \frac{8}{3}$

then substitute into the first to get y.
• Feb 5th 2009, 06:35 AM