Let to get
.
Now solve for , and then you can find .
I got it out with the first method. It was beautiful.
The second method I tried and I don't know what I did wrong but I couldn't get it out.
I got to here:
subtracted 30.25x from both sides and then plugged it into the quadratic formula.
But kept getting two answers, neither of which was the answer to the first method which was also the answer in the back of the book. I must have punched some number into my calculator wrongly.
I will move on now.
Thankyou both for your help
Cheers.
David.