so we need to add a amount, which is , to make the left hand side the correct form for "completing the square". We cannot just add this term... we will also need to add the same amount to the other side too, to keep the equation "balanced":
The LHS can be re-written automatically as ... this is the whole point of doing what we did.
And now we need to work out the RHS.. use a calculator or do it longways, for practice...
and now scale up the other fraction to have the same denominator:
and hopefully you spot that 121/441 will be a lovely number when square rooted... or or or or or
