b)P(x)=x2-2x+1
=>P(x)=(x-1)2
P(x) có No=1;ko có N0 âm
P(x)= x2-x-x+1
P(x)= x.(x-1)-(x-1)
P(x)=(x-1)(x-1)
P(x)=(x-1)2 (vô nghiệm)
=> P (x) vô nghiệm
a)tìm các cặp số nguyên x;y thỏa mãn (2x-)(x+1)=|y+1|
b)\(\left|x+\dfrac{1}{1.3}\right|+\left|x+\dfrac{1}{3.5}\right|+\left|x+\dfrac{1}{5.7}\right|+...+\left|x+\dfrac{1}{97.99}\right|=50x\)
cho A=\(\left(\dfrac{1}{2^2}-1\right).\left(\dfrac{1}{3^2}-1\right).\left(\dfrac{1}{4^2}-1\right)...\left(\dfrac{1}{100^2}-1\right)\)hãy so sánh A với \(\dfrac{-1}{2}\)
Cho A = \(\left(\dfrac{1}{2^2}-1\right).\left(\dfrac{1}{3^2}-1\right).\left(\dfrac{1}{4^2}-1\right)....\left(\dfrac{1}{100^2}-1\right)\)
So sánh A với \(\dfrac{-1}{2}\)
Cho A = \(\left(\dfrac{1}{2^2}-1\right).\left(\dfrac{1}{3^2}-1\right).\left(\dfrac{1}{4^2}-1\right)...\left(\dfrac{1}{100^2}-1\right)\)
So sánh A với \(-\dfrac{1}{2}\)
Bài 1: a) Cho \(A=\left(\dfrac{1}{2}-1\right)\left(\dfrac{1}{3}-1\right)...\left(\dfrac{1}{2015}-1\right)\left(\dfrac{1}{2016}-1\right)\). So sánh A với \(\dfrac{-1}{2015}\)
b) Cho biểu thức \(A=\dfrac{3x^3-x^2-3x+2015}{3x^4-x^3+3x+2014}\). Tính giá trị của biểu thức với x=\(\dfrac{1}{3}\)
A=\(\left(\dfrac{1}{2^2}-1\right).\left(\dfrac{1}{3^2}-1\right).\left(\dfrac{1}{4^2}-1\right).....\left(\dfrac{1}{100^2}-1\right)\)
So sánh A voi \(\dfrac{1}{2}\)
Bài 1: Tính
\(N=\left(\dfrac{1}{4.9}+\dfrac{1}{9.14}+\dfrac{1}{14.19}+...+\dfrac{1}{44.49}\right).\dfrac{1-3-5-7-...-9}{89}\)
Bài 2 : Rút gọn
a) A = |2x + 4,6| - 2x + 15,4
b) B = |x + 7,2| - |x - 1,2|
c) C = 8,5x - 19, 5 - |1,5x + 4,5|
d) D = 8,5 + x - |8,5 - x|
Bài 3 : Tìm x và y \(\in\) N.Biết 25 - y2 = 8(x - 2009)2
Bài 4 ; Cho :
\(A=\left(\dfrac{1}{2^2}-1\right)\left(\dfrac{1}{3^2}-1\right)\left(\dfrac{1}{4^2}-1\right)...\left(\dfrac{1}{100^2}-1\right)\)
So sánh phân số sau vs \(\dfrac{-1}{2}\)
Tìm \(x\)
a) \(2.\left|\dfrac{1}{2}x-\dfrac{1}{3}\right|=1\dfrac{2}{5}\)
b) \(\left|\dfrac{1}{4}x-2\dfrac{1}{5}\right|=\left|0,6-\dfrac{2}{3}x\right|\)
c) \(\left|2x-\dfrac{1}{3}\right|=x+\dfrac{1}{2}\)
cho A=\(\left(\dfrac{1}{2^2}-1\right).\left(\dfrac{1}{3^2}-1\right)....\left(\dfrac{1}{100^2}-1\right)\)hãy so sánh A với \(\dfrac{-1}{2}\)
Tìm x
a)\(\left(x+5\right)^3\)=-64
b)\(\left(2x-3\right)^2\)=9
c)\(\dfrac{x}{\dfrac{4}{2}}\)=\(\dfrac{4}{\dfrac{x}{2}}\)
d)\(\dfrac{-32}{\left(-2\right)^n}\)=4
e)\(\dfrac{8}{2x}=4\)
g)\(\left(\dfrac{1}{2}\right)^{2x-1}=\dfrac{1}{8}\)
h)\(\left(\dfrac{1}{2}\right)^2.x=\left(\dfrac{1}{2}\right)^5\)
i) \(\left(\dfrac{-1}{3}\right)x=\dfrac{1}{81}\)
Câu 1:
a) \(\left|\left|3x-3\right|+2x+\left(-1\right)^{2016}\right|=3x+2017^0\)
b) Cho B = \(1+\dfrac{1}{2}.\left(1+2\right)+\dfrac{1}{3}.\left(1+2+3\right)+....+\dfrac{1}{x}.\left(1+2+3+...+4\right)=115\)(x thuộc số tự nhiên khác 0)
