P(x)=-2x^3-2x^2+6x-2
Q(x)=-1x^3-0x^2+4x-1
P(x)-Q(x)=-3x^3-2x^2+2x-3. Đúng hay sai?,mình cần câu trả lời gấp vì mai thi rồi
a. (2x + 5)(2x - 5)
b. (x2 + 3)(3 - x2 )
c. 3x(x -1)2 - 2x(x + 3)(x - 3) + 4x(x - 4)
d. 3x(4x - 3) - (2x -1)(6x + 5)
e. 4x(3x2 - x) - (2x + 3)(6x2 - 3x + 1)
f. (x - 2)(1x + 2)(x + 4)
\(\left(x^2+3\right)\left(3-x^2\right)\)
\(\left(x^2+3\right)\left(-x^2+3\right)\)
\(\left(-x^2+3\right).x^2+3\left(-x^2+3\right)\)
\(-x^2.x^2+3x^2+3\left(-x^2+3\right)\)
\(-x^2.x^2+3x^2-3x^2+9\)
\(-x^2.x^2+9\)
\(\left(2x+5\right)\left(2x-5\right)\)
\(2x\left(2x-5\right)+5\left(2x-5\right)\)
\(4x^2-10x+5\left(2x-5\right)\)
\(4x^2-10x+10x-25\)
\(4x^2-25\)
Các bạn làm giúp mình những câu này với ạ, ngày mai mình phải nộp bài rồi
Tìm x
(-3x-2)2 +(3x+5)(5-3x)= -7
(x+2)(x2+2x+2)-x(x-8)2=(4x-3)(4x+3)
(2x+3)3-x(x+2)2+(x+5)(x-4)=(2x-1)(4x2+2x+1)+18x(2x+3)
\(\left(-3x-2\right)^2+\left(3x+5\right)\left(5-3x\right)=-7\)
\(\Leftrightarrow9x^2+12x+4+15x-9x^2+25-15x=-7\)
\(\Leftrightarrow12x+36=0\Leftrightarrow x=-3\)
\(\left(x+2\right)\left(x^2+2x+2\right)-x\left(x-8\right)^2=\left(4x-3\right)\left(4x+3\right)\)
\(\Leftrightarrow x^3+2x^2+2x+2x^2+4x+4-x\left(x^2-16x+64\right)=16x^2-9\)
\(\Leftrightarrow x^3+4x^2+6x+4-x^3+16x^2-64=16x^2-9\)
\(\Leftrightarrow4x^2+6x-51=0\)
\(\cdot\Delta=6^2-4.4.\left(-51\right)=852\)
Vậy pt có 2 nghiệm phân biệt
\(x_1=\frac{-6+\sqrt{852}}{8}\);\(x_2=\frac{-6-\sqrt{852}}{8}\)
giải giùm mình nha!!!
a)(x^2 +2x +1)/(x^2+2x+2)+(x^2+2x+2)/(x^2+2x+3)=7/6
b)(x^2+2x+2)/(x+1) +(x^2 +8x+20)/(x+4)=(x^2+4x+6)/(x+2)+(x^2+6x+12)/(x+3)
c)(x+4)/(x^2-3x+2) +(x+1)/(x^2-4x+3)=(2x+5)/(x^2-4x+5).
giúp mình nhé, bài này mình cần gấp. Mình cảm ơn nhiều nhiều.
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P)(9-x)(x^2+2x-3) n)(-x+3)(x^2+x+1) O)(-6x+1/2)(x^2-4x+2) q)(6x+1)(x^2-2x-3) r)(2x+1)(-x^2-3x+1) U)(2x-3)(-x^2+x+6) s)(-4x+5)(x^2+3x-2) V)(-1/2x+3)(2x+6-4x^3)
p) \(\left(9-x\right)\left(x^2+2x-3\right)\)
\(=9\left(x^2+2x-3\right)-x\left(x^2+2x-3\right)\)
\(=9x^2+18x-27-x^3-2x^2+3x\)
\(=-x^3+7x^2+21x-27\)
n) \(\left(-x+3\right)\left(x^2+x+1\right)\)
\(=-x\left(x^2+x+1\right)+3\left(x^2+x+1\right)\)
\(=-x^3-x^2-x+3x^2+3x+3\)
\(=-x^2+2x^2+2x+3\)
o) \(\left(-6x+\dfrac{1}{2}\right)\left(x^2-4x+2\right)\)
\(=-6x\left(x^2-4x+2\right)+\dfrac{1}{2}\left(x^2-4x+2\right)\)
\(=-6x^3+24x^2-12x+\dfrac{1}{2}x^2-2x+1\)
\(=-6x^3+\dfrac{49}{2}x^2-14x+1\)
q) \(\left(6x+1\right)\left(x^2-2x-3\right)\)
\(=6x\left(x^2-2x-3\right)+\left(x^2-2x-3\right)\)
\(=6x^3-12x^2-18x+x^2-2x-3\)
\(=6x^3-11x^2-20x-3\)
r) \(\left(2x+1\right)\left(-x^2-3x+1\right)\)
\(=2x\left(-x^2-3x+1\right)+\left(-x^2-3x+1\right)\)
\(=-2x^3-6x^2+2x-x^2-3x+1\)
\(=-2x^3-7x^2-x+1\)
u) \(\left(2x-3\right)\left(-x^2+x+6\right)\)
\(=2x\left(-x^2+x+6\right)-3\left(-x^2+x+6\right)\)
\(=-2x^3+2x^2+12x+3x^2-3x-18\)
\(=-2x^3+5x^2+9x-18\)
s) \(\left(-4x+5\right)\left(x^2+3x-2\right)\)
\(=-4x\left(x^2+3x-2\right)+5\left(x^2+3x-2\right)\)
\(=-4x^3-12x^2+8x+5x^2+15x-10\)
\(=-4x^3-7x^2+23x-10\)
v) \(\left(-\dfrac{1}{2}x+3\right)\left(2x+6-4x^3\right)\)
\(=-\dfrac{1}{2}x\left(2x+6-4x^3\right)+3\left(2x+6-4x^3\right)\)
\(=-x^2-3+2x^4+6x+18-12x^3\)
\(=2x^4-12x^3-x^2+6x+15\)
p: (-x+9)(x^2+2x-3)
=-x^3-2x^2+3x+9x^2+18x-27
=-x^3+7x^2+21x-27
n: (-x+3)(x^2+x+1)
=-x^3-x^2-x+3x^2+3x+3
=-x^3+2x^2+2x+3
o: (-6x+1/2)(x^2-4x+2)
=-6x^3+24x^2-12x+1/2x^2-2x+1
=-64x^3+49/2x^2-14x+1
q: (6x+1)(x^2-2x-3)
=6x^3-12x^2-18x+x^2-2x-3
=6x^3-11x^2-20x-3
r: (2x+1)(-x^2-3x+1)
=-2x^3-6x^2+2x-x^2-3x+1
=-2x^3-7x^2-x+1
u: =-2x^3+2x^2+12x+3x^2-3x-18
=-2x^3+5x^2+9x-18
s: =-4x^3-12x^2+8x+5x^2+15x-10
=-4x^3-7x^2+23x-10
A(x)=5x^5+3x-4x^4-2x^3+6+4x^2
Q(x)=2x^4-x+3x^2-2x^3+1/4-x^5
a, thu gọn và sắp xếp theo lũy thừa giảm dần
b. tính P(x)+Q(x), P(x)-Q(x)
c)chứng tỏ rằng x=-1 là nghiệm của P(x) nhg ko phải là nghiệm của Q(X)
mong mọi người trả lời nhanh giúp ạ
Bài 1: Nhân
a) 4x(3x-1)-2(3x+1)-(x+3)
b) (-2x^2-1xy+2y^2)(-1x^2y)
c) 4x(3x^2-x) -(2x+3)^2(6x^2-3x+1)
d) (x-2)(x+2)(x+4)
Bài 2: Tìm x
a) 4x(x-1)-3(x^2-5)-x^2=(x-3)(x+4)
b) 2(3x-1)(2x+5-6)(2x-1)(x+2)=6
c) 3(2x-1)(3x-1)-(2x-3)(9x-1)-3=-3
Bài 1:
a) \(4x\left(3x-1\right)-2\left(3x+1\right)-\left(x+3\right)\)
\(=12x^2-4x-6x-2-x-3\)
\(=12x^2-11x-5\)
b) \(=\left(-2x^2-1xy+2y^2\right)\left(-1x^2y\right)\)
\(=\left[\left(-1x^2y\right)\left(-2x^2\right)\right]-\left[\left(-1x^2y\right).1xy\right]+\left[\left(-1x^2y\right).2y^2\right]\)
\(=\left(2x^4y\right)-\left(-1x^3y^2\right)+\left(-2x^2y^3\right)\)
\(=2x^4y+1x^3y^2-2x^2y^3\)
c) \(4x\left(3x^2-x\right)-\left(2x+3\right)^2\left(6x^2-3x+1\right)\)
\(=\left(4x.3x^2\right)-\left(4x.x\right)-\left[\left(2x\right)^2+2.2x.3+3^2\right]\left(6x^2-3x+1\right)\)
\(=12x^3-4x^2-\left(4x^2+12x+9\right)\left(6x^2-3x+1\right)\)
\(=12x^3-4x^2-\left[4x^2\left(6x^2-3x+1\right)+12x\left(6x^2-3x+1\right)+9\left(6x^2-3x+1\right)\right]\)
\(=12x^3-4x^2-\left[\left(24x^4-12x^3+4x^2\right)+\left(72x^3-36x^2+12x\right)+\left(36x^2-27x+9\right)\right]\)
\(=12x^3-4x^2-24x^4+12x^3-4x^2-72x^3+36x^2-12x-36x^2+27x-9\)
\(=-48x^3-8x^2-24x^4+15x-9\)
Nếu ai bít thì hãy trả lời hộ mình nhé mình không biết các con tìm x này nếu, ai đang online thì trả lời hộ mình nhé mình đang rất cần gấp. 1, 2x-5.(x+1)=4x-3. 2, (3x+2)-(5x+7)=4x-3. 3, - (6x-2-7)+(3-2x)=0. 4,| 3-x|=5-2x. . 5, -3.(-2-7)-(-3+2)-(-4).
2/3-1/3x(X-3/2)-1/2x(2X+1)=5
mình cần câu trả lời gấp, cảm ơn mọi người nhiều
\(\frac{2}{3}-\frac{1}{3}\left(x-\frac{3}{2}\right)-\frac{1}{2}\left(2x+1\right)=5\)
=> \(\frac{2}{3}-\frac{1}{3}x+\frac{1}{2}-x-\frac{1}{2}=5\)
=> \(\left(\frac{2}{3}+\frac{1}{2}-\frac{1}{2}\right)+\left(-\frac{1}{3}x-x\right)=5\)
=> \(\frac{2}{3}-\frac{4}{3}x=5\)
=> \(\frac{4}{3}x=\frac{2}{3}-5=-\frac{13}{3}\)
=> \(x=-\frac{13}{4}\)
\(A\left(x\right)=2x^3+4x^2-x-1\)
+
\(B\left(x\right)=2x^3-2x^2-x-3\)
=\(P\left(x\right)=4x^3-6x^2-4\)
(a): đúng
(b): sai
\(A\left(x\right)+B\left(x\right)=2x^3+4x^2-x-1+2x^3-2x^2-x-3\\ =\left(2x^3+2x^3\right)+\left(4x^2-2x^2\right)+\left(-x-x\right)+\left(-1-3\right)\\ =4x^3+2x^2-2x-4\ne P\left(x\right)\)
=> Chọn B. Sai