X4+5x=120;b1x3+4x15=180
x4 +5x =120
x=............
Tìm x
a) x4+5x=120
b)1x3+4x+15=180
lớp 3 đã học x4 = x nhân 4 rooif à
hay đề sai
a, x4 + 5x=120
=> 10*x+4+50+x=120
=>11*x+54=120
=>11*x=120-54=66
=>x=66/11
=>x=6
b,1x3+4x+15=180
=>103 + 10*x + 40 +x +15 = 180
=>158 +11*x = 180
=>11*x = 180-158=22
=>x=22/11
=>x=2
(dấu * là dấu nhân; dấu / là dấu chia nha =))
Bài 1: Phân tích đa thức thành nhân tử
a) x3-2x2-5x+6
b) x4+5x2+6
c) x3+4x2+5x+2
d) x4+324
P=
\(\frac{\text{2x 3 x4+ 2 x3x 4 x2018 +2 x3 x4 x2019 -2x3 x4 x2020}}{\text{5 x6 x7+ 5x 6 x7 x2018 +5 x6 x7 x2019- 5x 6 x7 x2020}}\)
HELP ME !!!
Ta có \(\frac{2.3.4+2.3.4.2018+2.3.4.2019-2.3.4.2020}{5.6.7+5.6.7.2018+5.6.7.2019-5.6.7.2020}\)
\(=\frac{2.3.4\left(1+2018+2019-2020\right)}{5.6.7.\left(1+2018+2019-2020\right)}=\frac{2.3.4}{5.6.7}=\frac{4}{35}\)
Biết rằng \left(x^{4}-4\right)\left(-2x^{3}+5x-3\right) = -2x^{7}+5x^{5}-3x^{4}+8x^{3}-20x+12(x4−4)(−2x3+5x−3)=−2x7+5x5−3x4+8x3−20x+12.
Kết quả phép nhân \left(-x^{4}+4\right)\left(-2x^{3}+5x-3\right)(−x4+4)(−2x3+5x−3) là ?
X4 + 4 = 5X( X2 - 2)
\(x^4+4=5x\left(x^2-2\right)\)
\(\Leftrightarrow x^4-5x^3+10x+4=0\)
\(\Leftrightarrow\left(x+1\right)\left(x^3-6x^2+6x+4\right)=0\)
\(\Leftrightarrow\left(x+1\right)\left(x-2\right)\left(x^2-4x-2\right)=0\)
\(\Leftrightarrow\left[{}\begin{matrix}x+1=0\\x-2=0\\x^2-4x-2=0\end{matrix}\right.\)
\(\Leftrightarrow\left[{}\begin{matrix}x=-1\\x=2\\x=2\pm\sqrt{6}\end{matrix}\right.\)
\(X^4+4=5X\left(X^2-2\right)\\ \Leftrightarrow X^4-5X^3+10X+4=0\\ \Leftrightarrow\left(X+1\right)\left(X-2\right)\left(X^2-4X-2\right)\)
\(\left[{}\begin{matrix}X+1=0\\X-2=0\\X^2-4X-2=0\end{matrix}\right.\Leftrightarrow\left[{}\begin{matrix}X=-1\\X=2\\X=2+\sqrt{6}\\X=2-\sqrt{6}\end{matrix}\right.\)
VẬY......
Câu 1 : Thu Gọn Đa Thức P = x4 + x3 - x2 - x4 + 3x2 - 5x -1 ( khoanh tròn )
A. P = x4 + 2x2 - 5x -1 B. P = x3 - 2x2 -5x -1
C. P = x3 + 2x2 - 5x - 1 D. P = x3 + 2x2 + 5x - 1
giúp mik với
\(P=x^4+x^3-x^2-x^4+3x^2-5x-1.\)
\(\Leftrightarrow P=\left(x^4-x^4\right)+x^3+\left(3x^2-x^2\right)-5x-1\)
\(\Leftrightarrow P=x^3+2x^2-5x-1\)
Vậy chọn D
a)x4 + 5x =120. b)1x3 + 4x + 15 = 180
a. => 5x= 56
x4 = 120 - 56 = 64 nhé
b => 4x=42
1x3 = 180 - ( 42 + 15 ) =133
a) 10x+4+50+x=120
11x+54=120
11x=120-54=66
x=6
b) Làm tương tự nha
phân tích đa thức thành nhân tử
a) x2- x- y2- y
b) x2- 2xy- y2-z2
c) 5x- 5y+ 4x- ay
d) 3x3- x2-21x+ 7
e) x3- 4x2- 8x- 8
f) x3- 5x2- 5x+ 1
g) x2y- xz+ z- y
h) x4- x3+ x2- 1
i) x4- x2+ 10x- 25
a: \(x^2-y^2-x-y\)
\(=\left(x-y\right)\left(x+y\right)-\left(x+y\right)\)
\(=\left(x+y\right)\left(x-y-1\right)\)
f: \(x^3-5x^2-5x+1\)
\(=\left(x+1\right)\left(x^2-x+1\right)-5x\left(x+1\right)\)
\(=\left(x+1\right)\left(x^2-6x+1\right)\)