a) x - 3/4 = 1/7
x = 1/7 + 3/4
x = 25/28
b) 15/x - 1/3 = 28/51
15/x = 28/51 + 1/3
15/x = 45/51
x = 15.51/45
x = 17
a) x - 3/4 = 1/7
x = 1/7 + 3/4
x = 25/28
b) 15/x - 1/3 = 28/51
15/x = 28/51 + 1/3
15/x = 45/51
x = 15.51/45
x = 17
Bài 1: Thực hiện phép tính:
a, \(\left(\frac{3}{8}+\frac{-3}{4}+\frac{7}{12}\right):\frac{5}{6}+\frac{1}{2}\)
b, \(\frac{-3}{7}.\frac{5}{9}+\frac{4}{9}.\frac{-3}{7}+2\frac{3}{7}\)
Bài 2: Tìm x
a, \(\frac{2}{3}.x-\frac{1}{2}.x=\frac{5}{12}\)
b, \(\left(2\frac{4}{5}x-50\right):\frac{2}{3}=51\)
1:Tính
a) \(\left(\dfrac{1}{7}.x-\dfrac{2}{7}\right).\left(\dfrac{-1}{5}.x-\dfrac{2}{5}\right)=0\)
b) \(\dfrac{1}{6}.x+\dfrac{1}{10}.x-\dfrac{4}{5}.x+1=0\)
2:So sánh:
a) A=\(\left(\dfrac{-46}{51}.0,32.\dfrac{17}{20}\right):\dfrac{64}{75}\)
B=\(\dfrac{-10}{11}.\dfrac{8}{9}+\dfrac{7}{8}.\dfrac{10}{11}\)
b) A=\(\dfrac{-1}{3}+\dfrac{0,2-0,375+\dfrac{5}{11}}{-0,3+\dfrac{9}{16}-\dfrac{15}{22}}\)
B=\(\dfrac{-43}{51}.\dfrac{19}{80}\)
Các bạn giúp mình với a, -2/3x=4/15 b, x+1/3=2/5-(-1/3) c, -2/3x+-3/7+1/2x=-5/6 d, 2x.(x-1/7)=0
Bài 1: Tìm số nguyên x, biết:
a)\(\dfrac{6}{x-3}\) = \(\dfrac{2}{3}\)
b) \(\dfrac{14}{13}\) = \(\dfrac{-28}{10-x}\)
c) \(\dfrac{1}{5}\) = \(\dfrac{x:4-1}{10}\)
d) \(\dfrac{x}{4}\)= \(\dfrac{1}{x}\)
e) \(\dfrac{x-2}{50}\) = \(\dfrac{2}{x-2}\)
giúp ưm
Bài 1 :Bỏ dấu ngoặc
2007-(7-3+4)
6+[(-5) + 4 - 1 ]
5-[(-6+8-2]
-10+(7-3+1)
Bài 2 Tím tất cả các ước của -15 và 8
Bài 3 Tìm x
-1 phần 3 = x phần 6
18 phần x = -6 phần 7
X- -3 phần 15 = -11 phần 14
X phần -15 = 2 phần 5 + 4 phần 5
X phần 12:= 3 phần x
a) -3 phần 5x + -7 phần 4 = 3 phần 10 b)(x- 7 phần 18) × 15 phần 27 = -10 phần 27 c) (2x + 3 phần 4 ) ÷ 2 phần 3 = 5 phần 8 d) 5 1 phần 3 × (x + 9 phần 4 ) =-10 2 phần 3
Bài 1: Tính nhanh
a, \(\frac{-3}{7}-\left(\frac{2}{3}-\frac{3}{7}\right)\)
b, \(\frac{2}{15}:\left(\frac{1}{3}.\frac{4}{5}-\frac{1}{3}.\frac{6}{5}\right)\)
Bài 2: Tìm x:
a, \(\frac{3}{4}+\frac{1}{4}.x=\frac{5}{8}\)
b, 25% . x+x= -1,25
Bài 1: Thực hiện phép tính
a, \(\frac{4}{9}.\frac{2}{6}\)
b, \(1\frac{1}{3}.\left(0,5\right)+\left(\frac{8}{15}-\frac{19}{30}\right):\frac{6}{15}\)
Bài 2: Tìm x, biết
a, \(\left(\frac{2}{7}.x+\frac{3}{7}\right):2\frac{1}{5}-\frac{3}{7}=1\)
HELP ME!!!!!!!!!!!!!
Bài 15:
a)\(\dfrac{-2}{5}\)+\(\dfrac{4}{5}\) . x =\(\dfrac{3}{5}\)
b)\(\dfrac{-3}{7}\) - \(\dfrac{4}{7}\):x = -2
Bài 16
a) x - \(\dfrac{10}{3}\) = \(\dfrac{7}{15}\) . \(\dfrac{3}{5}\)
b) x + \(\dfrac{3}{22}\)= \(\dfrac{27}{121}\) . \(\dfrac{11}{9}\)
c) \(\dfrac{8}{23}\) . \(\dfrac{48}{24}\) - x = \(\dfrac{1}{3}\)
d) 1 - x = \(\dfrac{49}{65}\).\(\dfrac{5}{7}\)
Bài 17: tìm x
a) \(\dfrac{62}{7}\) . x = \(\dfrac{29}{9}\): \(\dfrac{3}{56}\)
b) \(\dfrac{1}{5}\) : x=\(\dfrac{1}{5}\)+\(\dfrac{1}{7}\)
bài 18:
a)\(\dfrac{2}{5}\)+\(\dfrac{3}{4}\): x =\(\dfrac{-1}{2}\)
b)\(\dfrac{5}{7}\) - \(\dfrac{2}{3}\) . x = \(\dfrac{4}{5}\)
c) \(\dfrac{1}{2}\)x + \(\dfrac{3}{5}\)x = \(\dfrac{-2}{3}\)
d) \(\dfrac{4}{7}\).x-x = \(\dfrac{-9}{14}\)
bài 19: tính
\(\dfrac{1}{1.2}\)+\(\dfrac{1}{2.3}\)+\(\dfrac{1}{3.4}\)+...+ \(\dfrac{1}{2018.2019}\)
bài 20:tìm x
\(\dfrac{1}{1.2}\)+\(\dfrac{1}{2.3}\)+...+\(\dfrac{1}{x.\left(x+1\right)}\)=\(\dfrac{2008}{2009}\)
bài 21: tìm x
\(\dfrac{x+1}{99}\)+\(\dfrac{x+2}{98}\)\(\dfrac{x+3}{97}\)\(\dfrac{x+4}{96}\)=-4
bài 22 : so sánh các phân số sau:
a) \(\dfrac{-1}{5}\)+\(\dfrac{4}{-5}\)và 1
b) \(\dfrac{3}{5}\) và \(\dfrac{2}{3}\)+\(\dfrac{-1}{5}\)
c)\(\dfrac{3}{2}\)+\(\dfrac{-4}{3}\) và \(\dfrac{1}{10}\)+\(\dfrac{-4}{5}\)
d) \(\dfrac{1}{2}\)+\(\dfrac{1}{3}\)+\(\dfrac{1}{4}\)+\(\dfrac{1}{5}\)+\(\dfrac{1}{6}\) và 2