Hi There,
I’ve managed to get -240 by doing this:
9x^{2}y + 3y^{4}
When x=4 and y=-2 then:
= 9*4^{2}*-2 + 3*-2^{4}
= 9*16*-2 + 3*16
= -288 + 48
= -240
Hope this helps?
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 9x^{2}y+3y^{4 }when x=4 and y=-2. When I do ((9*4^{2})-2)+(3*-2^{4}) 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?