Please someone help me with this equation, I've been stuck on it for a while now.

This is Subtracting polynomials.

Subtract -4x^6+(-9x^2)+2x+(-8) from -8x^3+5x^2+3

Question

Please someone help me with this equation, I've been stuck on it for a while now.

This is Subtracting polynomials.

Subtract -4x^6+(-9x^2)+2x+(-8) from -8x^3+5x^2+3

anonymous · Answer

in subtracting polynomials, you'll have to subtract like terms.
let's let
P1 = -8x^3+5x^2+3
P2 = -4x^6+(-9x^2)+2x+(-8)

you're question is P1 - P2 correct?

anonymous · Answer

Yes.

anonymous · Answer

I've done the equation around 6 times already and it keeps on telling me it's wrong.

savvy · Answer

always use parenthesis while subtraction.....
(-8x^3 + 5x^2 + 3) - [-4x^6 + (-9x^2)+ 2x + (-8)]
remember when there is a + sign outside the parenthesis open the parenthesis by keeping the sign of all the terms same as inside the parenthesis and whenever there is a - sign outside the parenthesis just change the sign of all the terms inside the parenthesis....

savvy · Answer

try it now....

anonymous · Answer

since there is no x^6 term in P1, you can think of it as 0x^6.  So when we subtract P1 - P2 you'll have to take
0x^6 - (-4x^6)
can you simplify this?

savvy · Answer

also....you can subtract like terms...

anonymous · Answer

Ii also tried with the parenthesis...

anonymous · Answer

actually, savvy's method is better..

savvy · Answer

see in continuity of my reply on parenthesis....
since before the first brackett there is no sign we keep signs of all the terms as it is, so it is:
-8x^3 + 5x^2 + 3
and since there is a - sign outside the 2nd brackett we change all signs...
4x^6 - (-9x^2)- 2x - (-8)
now also there are - signs outside some more bracketts so changing sins again would make it
4x^6 + 9x^2 - 2x + 8
now the expression becomes
-8x^3 + 5x^2 + 3 + 4x^6 + 9x^2 - 2x + 8
now joining like terms
which are only the constant terms and terms with x^2....
we get
4x^6 - 8x^3 + 13x^2 - 2x + 11

anonymous · Answer

It still says that the answer is wrong...

campbell_st · Answer

the problem is 

$$-8x^3 +5x^2 + 3-(-4x^6 -9x^2+2x -8) = -8x^3 + 5x^2 + 3 + 4x^6 + 9x^2 -2x + 8 $$

which gives

$$4x^6 - 8x^3 + 14x^2 -2x +11$$

savvy · Answer

oh yaah....i went wrong with that addition in the terms wid x^2.....lol..

anonymous · Answer

@__@ It's okay! Thanks everyone! Everyone deserves a medal!

anonymous · Answer

Can you guys help me with another one?