a)x3-3x2 +2x≥0
b) 3/x+1≥7/3x+1
mn giúp mk với ạ❤
THỰC HIỆN PHÉP TÍNH
α) 3x.(x2_ 5x+7)
b) -2xy.(2x3+5x-1)
c) (x+4).(-x2+6x+5)
d) (x2-1).(2x2-3x+4)
e) (x+2y).(x-2y)
f) (-12x3y4+6xy2-18xy):6xy
g) (6x2y5-xy3+4x3y2):2xy
h) (3x-1)2-7.(x2+2)
i) (x3-3x2+5x-6):(x-2)
j) (x3+8y3):(x+2y)
Mn giúp em lm các bài này vs ạ em đang cần gấp.Em cảm trc ạ.
a)=\(3x^3-15x^2+21x\)
b)\(=-2x^4y-10x^2y+2xy\)
c)\(=-x^3+6x^2+5x-4x^2+24x+20=-x^3+2x^2+29x+20\)
d)\(=2x^4-3x^3+4x^2-2x^2+3x-4=2x^4-3x^32x^2+3x-4\)
e)\(=x^2-4y^2\)
f)\(=-2x^2y^3+y-3\)
g)\(=3xy^4-\dfrac{1}{2}y^2+2x^2y\)
h)\(=9x^2-6x+1-7x^2-14=2x^2-6x-13\)
i)\(=x^2-x-3\)
j)\(=\left(x+2y\right)\left(x^2-2y+4y^2\right):\left(x+2y\right)=x^2-2y+4y^2\)
Tính f(x) - g(x) với:
f(x) = x5 – 3x2 + x3 – x2 – 2x + 5
g(x) = x2 – 3x + 1 + x2 – x4 + x5
giúp với ạ
\(f\left(x\right)-g\left(x\right)=\left(x^5-3x^2+x^3-x^2-2x+5\right)-\left(x^2-3x+1+x^2-x^4+x^5\right)\)
\(f\left(x\right)-g\left(x\right)=x^5-3x^2+x^3-x^2-2x+5-x^2+3x-1-x^2+x^4-x^5\)
\(f\left(x\right)-g\left(x\right)=\left(x^5-x^5\right)+\left(-3x^2-x^2-x^2-x^2\right)+x^3+\left(-2x+3x\right)+\left(5-1\right)+x^4\)
\(f\left(x\right)-g\left(x\right)=-6x^2+x^3+x+4+x^4\)
\(f\left(x\right)-g\left(x\right)=x^4+x^3-6x^2+x+4\)
Cho D.ABC có M, N lần lượt là trung điểm của AB, AC biết BC = 6cm. Độ dài MN là
A.3cm
B.1cm
C.4cm
D.2cm
Hằng đẳng thức (x - 1)3 được viết đúng là
A.(x - 1)3 = x3 - 3x2 + 3x + 1
B.(x - 1)3 = x3 - 3x + 3x2 - 1
C.(x - 1)3 = x3 - 2x2 + 2x - 1
D.(x - 1)3 = x3 - 3x2 + 3x - 1
Bài 7. Tìm x,biết:
a) x-3x2=0 e) 5x(3x-1)+x(3x-1)-2(3x-1)=0
b) (x+3)2-x(x-2)=13 c) (x-4)2-36=0
d) x2-7x+12=0 g) x2-2018x-2019=0
Bài 8. Tìm x, biết
a) (2x-1)2=(x+5)2 b) x2-x+1/4
c) 4x4-101x2+25=0 d) x3-3x2+9x-91=0
Bài 1: Tìm x ∈ Z ,biết :
a, x+35= 2x+15+(13-4)
b, 5-2x =15-(-9)-3x
c, x+135 =3x -15
Mn giúp mk với ạ !!! Mk cảm ơn nhìu ạ !!😊❤
a, x+35= 2x+15+(13-4)
\(\Leftrightarrow x-2x=15-35+9\)
\(\Leftrightarrow-x=-11\)
\(\Leftrightarrow x=11\)
b, 5-2x =15-(-9)-3x
\(\Leftrightarrow-2x+3x=15+9-5\)
\(\Leftrightarrow x=19\)
c, x+135 =3x -15
\(\Leftrightarrow x-3x=-15-135\)
\(\Leftrightarrow-2x=-150\)
\(\Leftrightarrow x=\frac{-150}{-2}=75\)
a) x + 35 = 2x + 15 + ( 13 - 4 )
x - 2x = - 35 + 15 + 13 - 4
-x = - 20 + 9
-x = - 11
\(\Rightarrow\) x = 11
Vậy x = 11
b) 5 - 2x = 15 - ( -9 ) - 3x
-2x + 3x = 15 + 9 - 5
x = 24 - 5
x = 19
Vậy x = 19
c) x + 135 = 3x - 15
x - 3x = -135 - 15
-2x = -150
x = -150 : (-2)
x = 75
Vậy x = 75
Chúc bạn học tốt nha !
Tick cho mk nha bạn !
1. Tìm x,y:
a) (x+2)2 + (x-3)2 = 2x ( x+ 7)
b) x3- 3x2 + 3x - 126 = 0
c) x2 + y2 - 2x + 4y + 5 = 0
d) 2x2 - 2xy + y2 + 4x + 4 = 0
\(a.\left(x^2+4x+4\right)+\left(x^2-6x+9\right)=2x^2+14x\)
\(x^2+4x+4+x^2-6x+9-2x^2-14x=0\)
\(-18x+13=0\)
\(x=\dfrac{13}{18}\)
Vậy \(S=\left\{\dfrac{13}{18}\right\}\)
\(b.\left(x-1\right)^3-125=0\)
\(\left(x-1\right)^3=125\)
\(x-1=5\)
\(x=6\)
Vậy \(S=\left\{6\right\}\)
\(c.\left(x-1\right)^2+\left(y +2\right)^2=0\)
\(Do\left(x-1\right)^2\ge0\forall x;\left(y+2\right)^2\ge0\forall y\)
\(\Rightarrow\left(x-1\right)^2+\left(y+2\right)^2\ge0\forall x,y\)
Mà \(\left(x-1\right)^2+\left(y+2\right)^2=0\)
\(\Rightarrow\left[{}\begin{matrix}\left(x-1\right)^2=0\\\left(y+2\right)^2=0\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x-1=0\\y+2=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=1\\y=-2\end{matrix}\right.\)
Vậy \(S=\left\{1;-2\right\}\)
\(d.x^2-4x+4+x^2-2xy+y^2=0\)
\(\left(x-2\right)^2+\left(x-y\right)^2=0\)
\(\Rightarrow\left[{}\begin{matrix}\left(x-2\right)^2=0\\\left(x-y\right)^2=0\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x-2=0\\x-y=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}x=2\\y=2\end{matrix}\right.\)
Vậy \(S=\left\{2;2\right\}\)
a) x2 - 4x + 4
b) x2 - 2
c) 1 - 8x3
d) x3 + 3x2 + 3x + 1
e) (x + y)2 - 9x
f)x2+6x+9
g)10x-25-x2
h)8x3-\(\dfrac{1}{8}\)
giúp em vs mn thx mn ạ
\(a,=\left(x-2\right)^2\\ b,=\left(x-\sqrt{2}\right)\left(x+\sqrt{2}\right)\\ c,=\left(1-2x\right)\left(1+2x+4x^2\right)\\ d,=\left(x+1\right)^3\\ e,Sửa:\left(x+y\right)^2-9x^2=\left(x+y-3x\right)\left(x+y+3x\right)\\ =\left(y-2x\right)\left(4x+y\right)\\ f,=\left(x+3\right)^2\\ g,=-\left(x^2-10x+25\right)=-\left(x-5\right)^2\\ h,=8\left(x^3-\dfrac{1}{64}\right)=8\left(x-\dfrac{1}{4}\right)\left(x^2+\dfrac{1}{4}x+\dfrac{1}{16}\right)\)
a) \(\left(x-2\right)^2\)
b) \(\left(x-\sqrt{2}\right)\left(x+\sqrt{2}\right)\)
c) \(\left(1-2x\right)\left(1+2x+4x^2\right)\)
d) \(\left(x+1\right)^3\)
e) \(\left(x+y-3\sqrt{x}\right)\left(x+y+3\sqrt{x}\right)\)
f) \(\left(x+3\right)^2\)
g) \(-\left(x-5\right)^2\)
h) \(\left(2x-\dfrac{1}{2}\right)\left(4x^2+x+\dfrac{1}{4}\right)\)
a)A=3x(2/3x2-3x4)+(3x2)(x3-1)+(-2+9).x2-12
b)B=x(2x3+x+2)-2x2(x2+1)+x2-2x+1
c)C=x.(2x+1)-x2(x+2)+x3-x+3
a, \(A=2x^3-9x^5+3x^5-3x^2+7x^2-12=-6x^5+2x^3+4x^2-12\)
b, \(B=2x^4+x^2+2x-2x^3-2x^2+x^2-2x+1=2x^4-2x^3+1\)
c, \(C=2x^2+x-x^3-2x^2+x^3-x+3=3\)
1) rút gọn biểu thức
a) (x2- 5)-(x+7)(x-7)
b)(2x+3y)2+(3x-2y)2-2(2x+3y)(2x+3y93x-2y)
2) tìm giá trị biểu thức
A= x3+3x2+3x+1 tại x = 99
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