|x| + | x+1| + | x+2|+... +| x+10| = 16x
Tìm x:
( 4x + 1 )( 16x^2 - 4x + 1 ) - 16x ( 4x^2 - 5 ) = 17
Tính giá trị biểu thức:
p=(x+1)(x^2-x+1)+x-(x-1)(x^2+x+1)+2010; x=-2010)
q=16x(4x^2-5)-(4x+1)(16x^2-4x+1); x=1/5
\(p=\left(x+1\right)\left(x^2-x+1\right)+x-\left(x-1\right)\left(x^2+x+1\right)+2010\)\(=\left(x^3+1\right)+x-\left(x^3-1\right)+2010=x^3+1+x-x^3+1+2010=x+2012\)Với \(x=-2010\Rightarrow p=-2010+2012=2\)
\(q=16x\left(4x^2-5\right)-\left(4x+1\right)\left(16x^2-4x+1\right)=64x^3-80x-64x^3-1=-80x-1\)Với \(x=\dfrac{1}{5}\Rightarrow q=-80.\dfrac{1}{5}-1=-17\)
Giải phương trình:
1, (x^2 - 10)^2 = 16x + 1
2, x^4 = 5x^2 + 8x + 12
3, (x + 3)(x + 4)(x + 5) = x
Tìm GTLN:
a) 1/2x - x^2
b) -x^2 + 16x -10
Tìm GTLN:
a) 1/2x - x^2
b) -x^2 + 16x -10
Ai rảnh giúp vs
a)x^2-5x+2x-10
b)x^2-7x-2x+14
c)x^3+8+5xy+10y
d)x^4+64+16x^2-16x^2
a) x(x-5)+2(x-5) = (x-5)(x+2)
b) (x-7)(x-2)
c) (x+2)(x^2+2x+4)+5y(x+2) = (x+2)(x^2+2x+4+5y)
d) (x^2+8)^2 -16x^2 = (x^2+8-4x)(x^2+8+4x)
C) 5x-(4-2x+x^2)(x+2)+x (x-1)(x+1)=0
D) (4x+1)(16x^2-4x+1)-16x (4x^2-5)=17
giải
5x-(4-2x+x^2)(x+2)+x(x-1)(x+1)=0
5x-(4x+8-2x^2-4x+x^3+2x^2)+x(x^2-1)=0
5x-4x-8+2x^2+4x-x^3-2x^2+x^3-1x=0
(5x-4x+4x-1x)+(-8)+(2x^2-2x^2)+(-x^3+x^3)=0
4x+(-8)=0
4x=0+8
4x=8
x=8:4
x=2
D)(4x+1)(16x^2-4x+1)-16x(4x^2-5)=17
64x^3-16x^2+4x+16x^2-4x+1-64x^3+80x=17
80x+1=17
80x=17-1
80x=16
x=1/5
\(5x-\left(4-2x+x^2\right)\left(x+2\right)+x\left(x-1\right)\left(x+1\right)=0\)
\(\Rightarrow5x-\left(4x-2x^2+x^3+8-4x+2x^2\right)+\left(x^2-x\right)\left(x+1\right)=0\)
\(\Rightarrow5x-\left(4x-2x^2+x^3+8-4x+2x^2\right)+\left(x^3+x-x^2-x\right)=0\)
\(\Rightarrow5x-4x+2x^2-x^3-8+4x-2x^2+x^3+x-x^2-x=0\)
\(\Rightarrow4x-8=0\Rightarrow4x=8\Rightarrow x=2\)
38. Chọn câu sai:
A. 16x^2 (x-y) - x + y= (2x-1) (2x+1)(4x^2+1)(x-y)
B. 16x^3 - 54y^5 = 2(2x -3y) (4x^2 + 6xy + 9y^2)
C. 16x^5 - 54y = 2(2x-3y) (2x + 3y)^2
D. 16x^4 (x-y) - x + y = (4x^2 -1 (4x^2 +1) (x-y)
Tìm x :
16x + 40 = 10 . 3 mũ 2 + 5 . ( 1 + 2 + 3 )
Ta có: \(16x+40=10\cdot3^2+5\cdot\left(1+2+3\right)\)
\(\Leftrightarrow16x+40=90+5\cdot6=120\)
hay x=5
x ^ 4 + 5x ^ 3-x ^ 2-16x + 10 = 0
x4+5x3-x2-16x+10=0
<=>x4+3x3-5x2+2x3+6x2-10x-5x2-15x+25=0
<=>x2(x2+3x-5)+2x(x2+3x-5)-5(x2+3x-5)=0
<=>(x2+2x-2)(x2+3x-5)=0
<=>x2+2x-2=0 hoặc x2+3x-5=0
Với x2+2x-2=0\(\Leftrightarrow x=\pm\sqrt{3}-1\)
Với x2+3x-5=0\(\Leftrightarrow\orbr{\begin{cases}x=-\frac{\sqrt{29}+3}{2}\\x=\frac{\sqrt{29}-3}{2}\end{cases}}\)