\(\dfrac{x+1}{10}+\dfrac{x+1}{11}+\dfrac{x+1}{12}=\dfrac{x+1}{13}+\dfrac{x+1}{14}\)
<=>(x+1)(1/10+1/11+1/12-1/13-1/14)=0
vì 1/10+1/11+1/12-1/13-1/14 khác 0 nên x+1=0<=>x=-1
vậy.........
tìm x
\(\dfrac{x+1}{10}+\dfrac{x+1}{11}+\dfrac{x+1}{12}=\dfrac{x+1}{13}+\dfrac{x+1}{14}\)
Tìm x, biết:
\(\dfrac{x-9}{11}+\dfrac{x-10}{12}+\dfrac{x-11}{13}=\dfrac{x-12}{14}+\dfrac{x-28}{15}\)
Tìm x, biết:
\(x=\dfrac{19}{11}\cdot\dfrac{5}{14}+\dfrac{1}{11}\cdot\dfrac{5}{7}-\sqrt{\dfrac{25}{4}}\cdot\dfrac{2}{11}\)
1
a) \(\left(x-1\right)^5=-243\)
b)\(\dfrac{x+2}{11}+\dfrac{2+x}{12}+\dfrac{x+2}{13}=\dfrac{+2x}{14}+\dfrac{x+2}{15}\)
c)x-2\(\sqrt{x}\)=0
Tìm số nguyên x ,nếu biết
a, \((\dfrac {1}{2}-\dfrac {1}{6}).3^x+3^{x+1}= 3^{16}+3^{13}\)
b, \((\dfrac {1}{2}-\dfrac {1}{3}).6^{x+2}-6^x = 6^{14}-6^{13}\)
c, \((\dfrac {1}{3}+\dfrac {1}{6}).2^{x+4}-2^x=2^{13}-2^{10}\)
d, \((\dfrac {1}{2}-\dfrac {1}{6}.3^{x+4} - 4.3^x =3^{16}-4.3^{13}\)
1. tìm x
a.\(\dfrac{1}{5}+x=\dfrac{13}{30}\)
b.\(\dfrac{1}{6}-x=\dfrac{5}{12}\)
c. \(x.\left(\dfrac{-1^{ }}{2}\right)^2=\dfrac{1}{16}\)
d. \(x:\dfrac{7}{11}=\dfrac{9}{33}\)
e. \(\dfrac{3}{5}.x=\dfrac{-21}{10}\)
1) Cho đa thức \(f\left(x\right)=x^{14}-14.x^{13}+14.x^{12}-...+13.x^2-14.x+14\) Tính f(13)
2) Tính : \(\left(\dfrac{3}{4}-81\right)\left(\dfrac{3^2}{5}-81\right)\left(\dfrac{3^3}{6}-81\right)...\left(\dfrac{3^{2000}}{2003}-81\right)\)
a,tìm x biết :\(\dfrac{x+11}{12}+\dfrac{x+11}{13}+\dfrac{x+11}{14}=\dfrac{x+11}{15}+\dfrac{x+11}{16}\) . THay x tìm được để thu gọn giá trị biểu thức \(A=1+x+x^2+x^3+...+x^{100}\)
b, Tính giá trị nhỏ nhất của : \(B=\left|x-2014\right|+\left|x-2013\right|+\left|x-2012\right|+\left|x-2011\right|+\left|x-2010\right|+2014\)
Câu 1: Tìm x
\(\dfrac{x+1}{10}+\dfrac{x+1}{11}+\dfrac{x+1}{12}=\dfrac{x+1}{13}+\dfrac{x+1}{14}\)
Câu 2: Tìm các số nguyên n để A có giá trị nguyên
a) \(A=\dfrac{3n+9}{n-4}\)
Câu 3: Cho hai số hữu tỉ \(\dfrac{a}{b}và\dfrac{c}{d}\) với mẫu dương, trong đó \(\dfrac{a}{b}< \dfrac{c}{d}CMR\)
\(\dfrac{a}{b}< \dfrac{a+c}{b+c}< \dfrac{c}{d}\)
help me
