b² - 2bc + c²
5² - 2(5)(-4) + -4²
25 - 10 x -8 + -16
= 89
Is this correct? If it is wrong please tell me where I messed up. Thanks!
2007-01-14 12:49:12 · 12 answers · asked by Lana 3 in Education & Reference ➔ Homework Help
OK you got the first steo right when you substituted the numbers for the variables. But you messed up a lil bit on your order of operations. First when you multiply a negative by a negative the answere becomes positive. -4 * -4 = +16. Next is the part with 2(5)(-4). The easiest and less complicated way to explain this is to first multiply -2*5 and get -10. Then you multiply -10*(-4) to get 40.
That makes your equation 25+40+16=81
2007-01-14 12:59:00 · answer #1 · answered by bradnick2000 3 · 0⤊ 0⤋
the result of 2bc is a negative number 25 - a - number equals a plus. result 25 + 80 - 16 = 89
my teachers made me write out every step
2007-01-14 13:04:34 · answer #2 · answered by Marjery B 2 · 0⤊ 0⤋
first substitute: (5)^2 - 2(5)(-4)+(-4)^2
then do exponents: 25 - 2(5)(-4)+16
then multiply: 25 - (-40) + 16
then add: 25+40+16 = 81
your errors: c = -4, so squared it is +16
also, the don't use the distributive property for the 2. Just multiply.
Remember, minus a negative is plus a positive
2007-01-14 13:01:22 · answer #3 · answered by Ckat219 1 · 0⤊ 0⤋
Dear Student,
You have a couple of mistakes.
The center section is wrong. You are using the distributive property when it doesn't apply. Just take 2x5x(-4) = -40
The 3rd section is (-4)squared . . . . =16; instead of the opposite of 4squared.. . .which would be -16.
Does this make sense?
corrected the sentence would be :
25 - (-40) + 16 = ?
Got it?
Good luck!
2007-01-14 12:59:26 · answer #4 · answered by Tj aka Mom 3 · 0⤊ 0⤋
I agree with
25-(-40)+16=81
as (2*5*-4) = -40 not 40
2007-01-14 13:03:03 · answer #5 · answered by Anonymous · 0⤊ 0⤋
I got 49 for the final answer. I believe you messed up in your second step. It should be:
25 - (-40) + -16 , I believe. Someone double check me?
2007-01-14 12:57:46 · answer #6 · answered by Mika 2 · 0⤊ 0⤋
I got 81. -4 squared is 16.
25-(-40)+16=81
2007-01-14 12:57:33 · answer #7 · answered by sarah15203 2 · 0⤊ 1⤋
25 - (-80)+ -16
-55 + -16
= 71
You must do the multiplication before the addition or subtraction.
2007-01-14 13:03:04 · answer #8 · answered by Inquisitive125 3 · 0⤊ 0⤋
b squared = 25
2bc = 2 (5)(-4) = 40
c squared = 16
25 - 40 + 16 = 1
So no you were wrong, sorry.
2007-01-14 12:57:22 · answer #9 · answered by Energetic Tomboy 2 · 0⤊ 0⤋
yes its wrong. 25-40+16=1 you all ways do p.e.m.d.a.s
witch stands 4. (),exponets,x,/,+,-
2007-01-14 12:56:48 · answer #10 · answered by Anonymous · 0⤊ 0⤋