Tải trên điện thoaaij về phần mềm PhotoMath thì bạn sẽ có đáp án và bài giải bài thực hiện phép tính này. Nếu thắc mắc về cánh sử dụng thì seach mạng.

\(2xy\left(x^2+xy-3y^2\right)\)

\(=2xy.x^2+2xy.xy-2xy.3y^2\)

\(=2x^3y+2x^2y^2-6xy^3\)

a: P(x)=6x^3-4x^2+4x-2

Q(x)=-5x^3-10x^2+6x+11

M(x)=x^3-14x^2+10x+9

b: \(C\left(x\right)=7x^4-4x^3-6x+9+3x^4-7x^3-5x^2-9x+12\)

=10x^4-11x^3-5x^2-15x+21

\(a,=2x^3y+2x^2y^2-6xy^3\\ b,=3x^3+6x^2-4x-8\\ c,=\left(4x^2+16x-20x-80+76\right):\left(x+4\right)\\ =\left[\left(x+4\right)\left(4x-20\right)+76\right]:\left(x+4\right)\\ =4x-20\left(dư.76\right)\\ d,=\left(x^4-x^2-x^3+x-2x^2+2\right):\left(x^2-1\right)\\ =\left(x^2-1\right)\left(x^2-x-2\right):\left(x^2-1\right)\\ =x^2-x-2\)

em mới lp 7 =)))

\(a,=4x^2+3xy-y^2+4xy-4x^2=7xy-y^2\\ b,=x^2-9-x^3+3x+x^2-3=-x^3+2x^2+3x-12\\ c,=-2x^2+12x-18+5x^2+4x-1=3x^2+16x-19\\ d,=8x^3+1-3x^3+6x^2=5x^3+6x^2+1\\ e,=\left(3x^2+4x+15x+20\right):\left(3x+4\right)\\ =\left(3x+4\right)\left(x+5\right):\left(3x+4\right)\\ =x+5\\ f,=\left(x^3+4x^2-3x+3x^2+12x-9+3x+3\right):\left(x^2+4x-3\right)\\ =\left[\left(x^2+4x-3\right)\left(x+3\right)+3x+3\right]:\left(x^2+4x-3\right)\\ =x+3\left(dư.3x+3\right)\)

\(a,2xy\left(x^2+xy-3y^2\right)=2x^3y+2x^2y^2-6xy^3\)

\(b,\left(x+2\right)\left(3x^2-4x\right)=3x^3-4x^2+6x^2-8x=3x^3+2x^2-8x\)

\(c,\left(3+3x^2-8x-20\right):\left(x+2\right)=3x-14\left(dư:11\right)\)

c: \(=\dfrac{x^3+2x^2+x^2+2x-10x-20}{x+2}\)

\(=x^2+x-10\)

b: \(\left(x^2+10x+8\right)^2-\left(8x+4\right)\left(x^2+8x+7\right)\)

\(=\left\lbrack\left(x^2+8x+7\right)+\left(2x+1\right)\right\rbrack^2-4\left(2x+1\right)\left(x^2+8x+7\right)\)

\(=\left(x^2+8x+7\right)^2+2\left(x^2+8x+7\right)\left(2x+1\right)+\left(2x+1\right)^2-4\left(2x+1\right)\left(x^2+8x+7\right)\)

\(=\left(x^2+8x+7\right)^2-2\left(x^2+8x+7\right)\left(2x+1\right)+\left(2x+1\right)^2\)

\(=\left(x^2+8x+7-2x-1\right)^2=\left(x^2+6x+6\right)^2\)

d: \(B=x^4+4x^3+8x^2+8x+4\)

\(=x^4+2x^3+2x^2+2x^3+4x^2+4x+2x^2+4x+4\)

\(=x^2\left(x^2+2x+2\right)+2x\left(x^2+2x+2\right)+2\left(x^2+2x+2\right)\)

\(=\left(x^2+2x+2\right)\left(x^2+2x+2\right)=\left(x^2+2x+2\right)^2\)

e: \(C=x^4-2x^3+5x^2-4x+4\)

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

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

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

Câu 1: C

Câu 2: B

a: \(A\left(x\right)=5x^5-4x^4-2x^3+4x^2+3x+6\)

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

b: \(A\left(x\right)+B\left(x\right)=4x^5-2x^4-4x^3+7x^2+2x+10\)

\(A\left(x\right)-B\left(x\right)=6x^5-6x^4+x^2+4x+2\)