solve the following system:

2^(x+3y) = 128

Printable View

- Apr 21st 2009, 07:28 PMmath123456Solving an exponential equation with two unknowns
solve the following system:

2^(x+3y) = 128 - Apr 21st 2009, 07:31 PMmr fantastic
- Apr 21st 2009, 07:33 PMIAmLegendToo
Not 100% sure here, but.

To solve for y.

Rewrite 128 as 2 to the something power, which is:

2 to the 7th power.

Set x+3y equal to 7.

x+3y = 7

3y = -x + 7

y = -(x-7)/3

Same for x, except solve x+3y = 7 for x.

x = -3y + 7

I believe this is how it's done. - Apr 21st 2009, 08:00 PMpickslides
- Apr 22nd 2009, 10:55 AMHallsofIvy
You said, in your first post, "Solve the following

**system**" (my emphasis). You did not give a system. What does the problem**really**say?