It's embarrassing that I can be thrown off by such a seemingly simple question, but I really cannot understand why one of my methods isn't working.
Question: Evaluate 9x2y+3y4 when x=4 and y=-2. When I do ((9*42)-2)+(3*-24) I get -336 but the correct answer is -240.
When I use the graphic calculator and just store x as 4 and y as -2 it gives me the -240. Help?