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28 tháng 4 2023

\(a,A\left(x\right)=2x^3-3x^2+2x+1\\ B\left(x\right)=3x^3+2x^2-x-5\\ b,A\left(x\right)+B\left(x\right)=\left(2x^3+3x^3\right)+\left(2x^2-3x^2\right)+\left(2x-x\right)+\left(1-5\right)=5x^3-x^2+x-4\\ A\left(x\right)-B\left(x\right)=\left(2x^3-3x^3\right)+\left(-3x^2-2x^2\right)+\left(2x+x\right)+\left(1-5\right)=-x^3-5x^2+3x-4\)

12 tháng 5 2023

`a,A(x)=2x^3+2x-3x^2+11`

`=2x^3-3x^2+2x+11`

`B(x)=2^2+3x^3-x-5`

`=3x^3+2x^2-x-5`

`b, A(x)+B(x)=(2x^3-3x^2+2x+11)+(3x^3+2x^2-x-5)`

`=2x^3-3x^2+2x+11+3x^3+2x^2-x-5`

`=(2x^3+3x^3)+(-3x^2+2x^2)+(2x-x)+(11-5)`

`=5x^3 -x^2 +x+6`

`c,A(x)-B(x)=(2x^3-3x^2+2x+11)-(3x^3+2x^2-x-5)`

`=2x^3-3x^2+2x+11- 3x^3 -2x^2+x+5`

`=(2x^3-3x^3)+(-3x^2-2x^2)+(2x+x)+(11+5)`

`=-x^3 -5x^2+3x+16`

12 tháng 5 2023

a/\(A\left(x\right)=2x^3+2x-3x^2+11\)
\(=2x^3-3x^2+2x+11\)
\(B\left(x\right)=2x^2+3x^3-x-5\)
\(=3x^3+2x^2-x-5\)
b/\(A\left(x\right)+B\left(x\right)=\left(2x^3-3x^2+2x+11\right)+\left(3x^3+2x^2-x-5\right)\)
\(=2x^3-3x^2+2x+11+3x^3+2x^2-x-5\)
\(=\left(2x^3+3x^3\right)-\left(3x^2-2x^2\right)+\left(2x-x\right)+\left(11-5\right)\)
\(=5x^3-x^2+x+6\)
c/\(A\left(x\right)+B\left(x\right)=\left(2x^3-3x^2+2x+11\right)-\left(3x^3+2x^2-x-5\right)\)
\(=2x^3-3x^2+2x+11-3x^3-2x^2+x+5\)
\(=\left(2x^3-3x^3\right)-\left(3x^2+2x^2\right)+\left(2x+x\right)+\left(11+5\right)\)
\(=-x^3-5x^2+3x+16\)
#DarkPegasus

a: A(x)=x^4+3x^3-2x^2+x+1

B(x)=2x^4-x^3+3x^2-4x-5

b: A(x)+B(x)

=x^4+3x^3-2x^2+x+1+2x^4-x^3+3x^2-4x-5

=3x^4+2x^3+x^2-3x-4

A(x)-B(x)

=x^4+3x^3-2x^2+x+1-2x^4+x^3-3x^2+4x+5

=-x^4+4x^3-5x^2+5x+6

AH
Akai Haruma
Giáo viên
13 tháng 5 2023

Lời giải:

a.

$A(x)=-x^5-7x^4-2x^3+x^2+4x+9$

$B(x)=x^5+7x^4+2x^3+2x^2-3x-9$

b. 

$A(x)+B(x)=(-x^5-7x^4-2x^3+x^2+4x+9)+(x^5+7x^4+2x^3+2x^2-3x-9)$

$=(-x^5+x^5)+(-7x^4+7x^4)+(-2x^3+2x^3)+(x^2+2x^2)+(4x-3x)+(9-9)=3x^2+x$

$A(x)-B(x)=(-x^5-7x^4-2x^3+x^2+4x+9)-(x^5+7x^4+2x^3+2x^2-3x-9)$

$=(-x^5-x^5)+(-7x^4-7x^4)+(-2x^3-2x^3)+(x^2-2x^2)+(4x+3x)+(9+9)=-2x^5-14x^4-4x^3-x^2+7x+18$

10 tháng 4 2020

dsssws

3 tháng 3 2023

mn giúp mk với ạ!

 

`@` `\text {Ans}`

`\downarrow`

`a)`

\(P(x) = 5x^3 + 3 - 3x^2 + x^4 - 2x - 2 + 2x^2 + x\)

`= x^4 + 5x^3 + (-3x^2 + 2x^2) + (-2x+x) + (3-2)`

`= x^4 + 5x^3 - x^2 - x + 1`

\(Q(x) = 2x^4 + x^2 + 2x + 2 - 3x^2 - 5x + 2x^3 - x^4\)

`= (2x^4 - x^4) + 2x^3 + (x^2 - 3x^2) + (2x-5x) + 2`

`= x^4 + 2x^3 - 2x^2 - 3x +2`

`b)`

`P(x)+Q(x) = (x^4 + 5x^3 - x^2 - x + 1) + (x^4 + 2x^3 - 2x^2 - 3x +2)`

`= x^4 + 5x^3 - x^2 - x + 1 + x^4 + 2x^3 - 2x^2 - 3x +2`

`= (x^4+x^4)+(5x^3 + 2x^3) + (-x^2 - 2x^2) + (-x-3x) + (1+2)`

`= 2x^4 + 7x^3 - 3x^2 - 4x + 3`

`P(x)-Q(x)=(x^4 + 5x^3 - x^2 - x + 1) - (x^4 + 2x^3 - 2x^2 - 3x +2)`

`= x^4 + 5x^3 - x^2 - x + 1 - x^4 - 2x^3 + 2x^2 + 3x -2`

`= (x^4 - x^4) + (5x^3 - 2x^3) + (-x^2+2x^2)+(-x+3x)+(1-2)`

`= 3x^3 + x^2 + 2x - 1`

`Q(x)-P(x) = (x^4 + 2x^3 - 2x^2 - 3x +2)-(x^4 + 5x^3 - x^2 - x + 1)`

`= x^4 + 2x^3 - 2x^2 - 3x +2-x^4 - 5x^3 + x^2 + x - 1`

`= (x^4-x^4)+(2x^3 - 5x^3)+(-2x^2+x^2)+(-3x+x)+(2-1)`

`= -3x^3 - x^2 - 2x + 1`

`@` `\text {Kaizuu lv u.}`

5 tháng 4 2023

1) a)

 \(A\left(x\right)=x^3+5x-7x^2-2x-12+3x^3\\ \text{ }=\left(x^3+3x^3\right)-7x^2+\left(5x-2x\right)-12\\ \text{ }=4x^3-7x^2+3x-12\)

\(B\left(x\right)=-2x^3+2x^2+12+5x^2-9x\\ \text{ }=-2x^3+\left(2x^2+5x^2\right)-9x+12\\ \text{ }=-2x^3+7x^2-9x+12\)

b)

\(A\left(x\right)+B\left(x\right)=\left(4x^3-7x^2+3x-12\right)+\left(-2x^3+7x^2-9x+12\right)\\ \text{ }=4x^3-7x^2+3x-12-2x^3+7x^2-9x+12\\ \text{ }=\left(4x^3-2x^3\right)+\left(7x^2-7x^2\right)-\left(9x-3x\right)+\left(12-12\right)\\ \text{ }=2x^3-6x\)

\(B\left(x\right)-A\left(x\right)=\left(-2x^3+7x^2-9x+12\right)-\left(4x^3-7x^2+3x-12\right)\\ \text{ }=-2x^3+7x^2-9x+12-4x^3+7x^2-3x+12\\ \text{ }=\left(-2x^3-4x^3\right)+\left(7x^2+7x^2\right)-\left(9x+3x\right)+\left(12+12\right)\\ \text{ }=6x^3+14x^2-12x+24\)

\(\left(4x-7\right)\cdot\left(x+5\right)\\ =4x\left(x+5\right)-7\left(x+5\right)\\ =4x\cdot x+4x\cdot5-7\cdot x-7\cdot5\\ =4x^2+20x-7x-35\)

6 tháng 5 2022

\(a)A\left(x\right)=5+3x^2-x-2x^2\)

\(A\left(x\right)=\left(3x^2-2x^2\right)-x+5\)

\(A\left(x\right)=x^2-x+5\)

\(B\left(x\right)=3x+3-x-x^2\)

\(B\left(x\right)=-x^2+\left(3x-x\right)+3\)

\(B\left(x\right)=-x^2+2x+3\)

\(b)C\left(x\right)=A\left(x\right)+B\left(x\right)\)

\(C\left(x\right)=\left(x^2-x+5\right)+\left(-x^2+2x+3\right)\)

\(C\left(x\right)=x^2-x+5+-x^2+2x+3\)

\(C\left(x\right)=\left(x^2-x^2\right)+\left(-x+2x\right)+\left(5+3\right)\)

\(C\left(x\right)=-x+8\)

\(c)D\left(x\right)=A\left(x\right)-B\left(x\right)\)

\(D\left(x\right)=\left(x^2-x+5\right)-\left(-x^2+2x+3\right)\)

\(D\left(x\right)=x^2-x+5+x^2-2x-3\)

\(D\left(x\right)=\left(x^2+x^2\right)+\left(-x-2x\right)+\left(5-3\right)\)

\(D\left(x\right)=2x^2-3x+2\)

6 tháng 5 2022

wá ghê gớm;-;