Bài 3: Nhân, chia số hữu tỉ
Các câu hỏi tương tự
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
Tìm \(x\in Q\), biết rằng :
a) \(\dfrac{11}{12}-\left(\dfrac{2}{5}+x\right)=\dfrac{2}{3}\)
b) \(2x\left(x-\dfrac{1}{7}\right)=0\)
c) \(\dfrac{3}{4}+\dfrac{1}{4}:x=\dfrac{2}{5}\)
1.\(\dfrac{-1}{4}-\dfrac{3}{4}:x=\dfrac{-11}{36}\)
2.\(\left(-1\dfrac{1}{5}+x\right):\left(-3\dfrac{3}{5}\right)=\dfrac{-7}{4}+\dfrac{1}{4}:\dfrac{1}{8}\)
tính giá trị của mỗi biểu thức A,B,C,D rồi sắp xếp các kết quả tìm được theo thứ tự tăng dần
Adfrac{5}{4}.left(5-dfrac{4}{3}right).left(-dfrac{1}{11}right) Bdfrac{3}{4}:left(-12right).left(-dfrac{2}{3}right)
Cdfrac{5}{4}:left(-15right).left(-dfrac{2}{5}right) Dleft(-3right).left(dfrac{2}{3}-dfrac{5}{4}right):left(-7right)
Đọc tiếp
tính giá trị của mỗi biểu thức A,B,C,D rồi sắp xếp các kết quả tìm được theo thứ tự tăng dần
A=\(\dfrac{5}{4}.\left(5-\dfrac{4}{3}\right).\left(-\dfrac{1}{11}\right)\) B=\(\dfrac{3}{4}:\left(-12\right).\left(-\dfrac{2}{3}\right)\)
C=\(\dfrac{5}{4}:\left(-15\right).\left(-\dfrac{2}{5}\right)\) D=\(\left(-3\right).\left(\dfrac{2}{3}-\dfrac{5}{4}\right):\left(-7\right)\)
a) Cho x3,7. So sánh:
A [x] + [x+dfrac{1}{5}] + [x+dfrac{2}{5}] + [x+dfrac{3}{5}] + [x+dfrac{4}{5}] và B[5x]
b)Tính [dfrac{100}{3}] + [dfrac{100}{3^2}] + [dfrac{100}{3^3}] + [dfrac{100}{3^4}]
c) Tính left[dfrac{50}{2}right]+left[dfrac{50}{2^2}right]+left[dfrac{50}{2^3}right]+left[dfrac{50}{2^4}right]+left[dfrac{50}{2^5}right]
Đọc tiếp
a) Cho x=3,7. So sánh:
A = [x] + [x+\(\dfrac{1}{5}\)] + [x+\(\dfrac{2}{5}\)] + [x+\(\dfrac{3}{5}\)] + [x+\(\dfrac{4}{5}\)] và B=[5x]
b)Tính [\(\dfrac{100}{3}\)] + [\(\dfrac{100}{3^2}\)] + [\(\dfrac{100}{3^3}\)] + [\(\dfrac{100}{3^4}\)]
c) Tính \(\left[\dfrac{50}{2}\right]+\left[\dfrac{50}{2^2}\right]+\left[\dfrac{50}{2^3}\right]+\left[\dfrac{50}{2^4}\right]+\left[\dfrac{50}{2^5}\right]\)
Tính :
a) -dfrac{3}{4}.31dfrac{11}{23}-0.75.8dfrac{12}{23}
b) left(2dfrac{1}{3}+3dfrac{1}{2}right):left(-4dfrac{1}{6}+3dfrac{1}{7}right)+7dfrac{1}{2}
c) 4dfrac{5}{9}:left(dfrac{-5}{7}right)+5dfrac{4}{9}:left(dfrac{-5}{7}right)
d) 4dfrac{25}{16}+25left(dfrac{9}{16}:dfrac{125}{64}:dfrac{-27}{8}right)
e) dfrac{2}{3}-4left(dfrac{1}{2}+dfrac{3}{4}right)
Đọc tiếp
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) \(\dfrac{2}{3}-4\left(\dfrac{1}{2}+\dfrac{3}{4}\right)\)
1,Tính giá trị biểu thức:
a, A=\(\dfrac{7}{35}+\left(-1\dfrac{3}{4}+\dfrac{12}{7}\right)-\left(\dfrac{1}{4}-\dfrac{2}{7}-\dfrac{13}{35}\right)-\dfrac{3}{7}\)
b, B=\(\sqrt{\dfrac{25}{16}-}\dfrac{\left(-3\right)^2}{\left|-4\right|}+\dfrac{\sqrt{\left(-7\right)^2}}{4}-3.\left(\dfrac{5}{2}\right)^2\)
Câu 1: Tim x, y biet:
a) 2.x-dfrac{5}{4}dfrac{20}{15}
b) left(x+dfrac{1}{3}right)^3left(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+1right)left(x-2right) 0
Câu 4: Thuc hien phep tinh:
Bleft(dfrac{3}{7}right)^{21}:left(dfrac{9}{49}right)^9
Đọc tiếp
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:
\(B=\left(\dfrac{3}{7}\right)^{21}:\left(\dfrac{9}{49}\right)^9\)
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) \(\dfrac{5}{9}:\left(\dfrac{1}{11}-\dfrac{5}{22}\right)+\dfrac{5}{9}:\left(\dfrac{1}{15}-\dfrac{2}{3}\right).\)