Solve for , giving an exact answer:
Expand the bracket. Distributing over the two inner terms:
Subtract the whole bracket, flipping both signs.
so the equation reads
Isolate and divide. Subtracting gives , hence
Convert to an exact fraction rather than rounding. Multiply numerator and denominator by and cancel:
since . Because is prime and does not divide , this fraction has a non-terminating decimal expansion, — unlike the neighbouring problem with on the right, which lands exactly on .
Decide how to report it. Give when an exact answer is wanted, or to two decimal places for a money-style context.
Check. exactly, and ; numerically .
Need to solve a different problem like this? Open the solver →