`(x+1)/3 = 9/(x+1)^2`
`(x+1)^3 = 3*9=27`
`(x+1)^3 =3^3`
`x+1=3`
`x=3-1=2`
Vậy `x=2`
\(< =>\left(x+1\right)\cdot\left(x+1\right)^2=9\cdot3< =>\left(x+1\right)^3=27< =>x+1=3< =>x=2\)
Câu 1: Tim x, y biet:
a) \(2.x-\dfrac{5}{4}=\dfrac{20}{15}\)
b) \(\left(x+\dfrac{1}{3}\right)^3=\left(\dfrac{-1}{8}\right)\)
Câu 2: Tim cac so a,b biet:
\(\dfrac{a}{2}=\dfrac{b}{3}\) va \(a+b=-15\)
Câu 3: Tim x \(\in\) Q biet:
\(\left(x+1\right)\left(x-2\right)< 0\)
Câu 4: Thuc hien phep tinh:
\(B=\left(\dfrac{3}{7}\right)^{21}:\left(\dfrac{9}{49}\right)^9\)
1.\(\dfrac{5}{7}+\dfrac{2}{3}\cdot x=\dfrac{3}{10}\)
2.\(\left(x-\dfrac{1}{2}\right):\dfrac{1}{3}+\dfrac{5}{7}=9\dfrac{5}{7}\)
Tìm tập hợp các số nguyên x, biết rằng :
\(4\dfrac{5}{9}:2\dfrac{5}{18}-7< x< \left(3\dfrac{1}{5}:3,2+4,5.1\dfrac{31}{45}\right):\left(-21\dfrac{1}{2}\right)\)
a)\(\dfrac{\dfrac{2}{3}-}{\dfrac{8}{3}-}\dfrac{\dfrac{2}{5}+}{\dfrac{8}{5}+}\dfrac{\dfrac{2}{7}-}{\dfrac{8}{7}-}\dfrac{\dfrac{2}{9}+}{\dfrac{8}{9}+}\dfrac{\dfrac{2}{11}}{\dfrac{8}{11}}\)
b)\(\left(\dfrac{1}{2}-1\right)\left(\dfrac{1}{3}-1\right)\left(\dfrac{1}{4}-1\right)...\left(\dfrac{1}{50}-1\right)\left(\dfrac{1}{51}-1\right)\)
Tìm x
a, \(\left(2-x\right)\times\left(\dfrac{4}{5}-x\right)< 0\)
b, \(\left(x-\dfrac{3}{2}\right)\times\left(2\times x-1\right)>0\)
c, \(\left(x-\dfrac{4}{7}\right)\div\left(x+\dfrac{1}{2}\right)>0\)
d, \(\left(2\times x-5\right)\div\left(x+1\dfrac{3}{4}\right)< 0\)
Giúp mk với
Tính :
a) \(-\dfrac{3}{4}.31\dfrac{11}{23}-0.75.8\dfrac{12}{23}\)
b) \(\left(2\dfrac{1}{3}+3\dfrac{1}{2}\right):\left(-4\dfrac{1}{6}+3\dfrac{1}{7}\right)+7\dfrac{1}{2}\)
c) \(4\dfrac{5}{9}:\left(\dfrac{-5}{7}\right)+5\dfrac{4}{9}:\left(\dfrac{-5}{7}\right)\)
d) \(4\dfrac{25}{16}+25\left(\dfrac{9}{16}:\dfrac{125}{64}:\dfrac{-27}{8}\right)\)
e) \(\dfrac{2}{3}-4\left(\dfrac{1}{2}+\dfrac{3}{4}\right)\)
Tính :
a) \(\left(\dfrac{-2}{3}+\dfrac{3}{7}\right):\dfrac{4}{5}+\left(\dfrac{-1}{3}+\dfrac{4}{7}\right):\dfrac{4}{5}\)
b) \(\dfrac{5}{9}:\left(\dfrac{1}{11}-\dfrac{5}{22}\right)+\dfrac{5}{9}:\left(\dfrac{1}{15}-\dfrac{2}{3}\right).\)
Tìm tập hợp các số nguyên \(x\), biết:
a) \(4\dfrac{5}{9}:2\dfrac{5}{8}-7< x< \left(3\dfrac{1}{5}:3,2+4,5.1\dfrac{31}{45}\right):\left(-21\dfrac{1}{2}\right)\)
b) \(\dfrac{-17}{21}:\left(\dfrac{5}{4}-\dfrac{2}{5}\right)< x+\dfrac{4}{7}< 1-\dfrac{1}{2}+\dfrac{1}{3}-\dfrac{1}{4}\)
Các bạn giúp mình với! Mình sẽ kick đúng cho ai trả lời đúng và trình bày khoa học
1.\(\dfrac{-1}{4}-\dfrac{3}{4}:x=\dfrac{-11}{36}\)
2.\(\left(-1\dfrac{1}{5}+x\right):\left(-3\dfrac{3}{5}\right)=\dfrac{-7}{4}+\dfrac{1}{4}:\dfrac{1}{8}\)
Bài 1: Tính
\(\dfrac{1}{2}.\dfrac{1}{-3}+\dfrac{1}{-3}.\dfrac{1}{4}+\dfrac{1}{4}.\dfrac{1}{-5}+\dfrac{1}{-5}.\dfrac{1}{6}\)
Bài 2: Tìm x ∈ Q:
\(\left(x-\dfrac{4}{7}\right).\left(x+\dfrac{1}{2}\right)>0\)
