Subtract 4x from both sides
Then divide both sides by 9 to isolate y
Y=(6-4x)/9
-- The area of the long skinny piece on top is (6 x 33) = 198
-- The length of the dotted line between the top and bottom pieces is (33-21) = 12
-- The area of the bottom piece is (12 x 15) = 180
-- The area of the whole thing is (198 + 180) = 378
-- The perimeter of the whole thing is (33 + 6 + 21 + 15 + 12 + 15 + 6) = 108
We write an inequality:



This equation cannot be solved using trivial methods found in high-school classes, so we resort to graphical examination.

is a linear function while

is an exponential one (with limit zero as

approaches

). We see that

at approximately

and

.
Indeed, using a computer algebra system such as the ones on modern TI calculators and on many internet sites gives equality at

. By observing our graph, we see that

when

or

.
the answer is A
you put 200 in the bank account. then wrote a check (taking out) for 20 and 30. then deposited (put in) 40