x Turn on thread page Beta
 You are Here: Home >< Maths

# C1 exponential equations watch

1. How do you solve 9x = 3x + 2. ? It is in a C1 paper so you can't use logs.
2. (Original post by jessyjellytot14)
How do you solve 9x = 3x + 2. ? It is in a C1 paper so you can't use logs.
well you know that

we also know that
3. (3^2)^x = 3^x+2
4. You can use the property of injectivity: . It uses logs implicitly though.
5. .
6. 9^x is the same as 3^2x, so you get 3^2x = 3^(x+2)
From there, 2x = x+2
If you can't solve 2x = x+2, god help you, my friend.

TSR Support Team

We have a brilliant team of more than 60 Support Team members looking after discussions on The Student Room, helping to make it a fun, safe and useful place to hang out.

This forum is supported by:
Updated: April 10, 2016
Today on TSR

### Loughborough better than Cambridge

Loughborough at number one

Poll
Useful resources

### Maths Forum posting guidelines

Not sure where to post? Read the updated guidelines here

### How to use LaTex

Writing equations the easy way

### Study habits of A* students

Top tips from students who have already aced their exams