\(2\left|\dfrac{1}{2}\right|-\dfrac{3}{2}=\dfrac{1}{4}\)
\(\Leftrightarrow2\left|\dfrac{1}{2}\right|=\dfrac{1}{4}+\dfrac{3}{2}\Rightarrow2\left|\dfrac{1}{2}\right|=\dfrac{7}{4}\)
\(\Leftrightarrow\left|\dfrac{1}{2}\right|=\dfrac{7}{4}:2\Rightarrow\left|\dfrac{1}{2}\right|=\dfrac{7}{8}\)....?
Tìm x:
a)12/16 = -x/4 = 21/y = z/80
b) 1/3.x+2/5.(x-1)=0
c) (2x-3).(6-2x)=0
d) -2/3-1/3.(2x-5)= 3/2
e) 2|1/2.x-1/3|-3/2=1/4
f) 1/3.x-1/2=4 và 1/2 (Hỗn số ý '^')
Bài 1: Thực hiện phép tính
a, A= -5/6. 3/10
b, B= 1/3- 1/4- +1/12
Bài 2: Tính hợp lí
A= (-1/5). 15/4+ |4/5- 14/5| : 8/3
B= (-1/2)^2 : 1/3/8 + 25%. 3/11
C= -8/5 +0,6+ |-1/2| +1/2
D= -5/9.2/13+ -5/9: 13/11 +1/5/9
Bài 3: Tìm x, biết:
a, x/2+3/4= 1/4
b, 3/5x + 0,4x = 2
c, x/-3= 7/6 + (-15/18)
d, Tìm x thuộc Z biết:
4/3. (1/6 -1/2) <x< 2/3. (-1/6 + 3/4)
TÌM X
A,\(\dfrac{3}{7}x-2\dfrac{1}{3}=0,5\)
b,\(\dfrac{4}{7}-\dfrac{2}{3}:x=1\dfrac{1}{4}\)
C,\(\left(\dfrac{2}{3}x+2\dfrac{1}{4}\right):3\dfrac{1}{5}=0,75\)
D,\(\left|\dfrac{4}{5}-\dfrac{2}{3}x\right|:\dfrac{1}{4}-\dfrac{2}{3}=1\)
GIÚP MÌNH NHÉ
Bài 2:Tìm x biết:
a)\(\dfrac{1}{7}+x=\dfrac{-2}{3}\)
b)\(\dfrac{-2}{3}:x=\dfrac{-5}{6}\)
c)\(\left\{\dfrac{3}{5}-2x\right\}.\dfrac{5}{8}=1\)
d)\(\dfrac{3}{4}+\dfrac{2}{5}x=\dfrac{29}{60}\)
e)\(\dfrac{3}{4}+\dfrac{1}{4}:x=\dfrac{2}{5}\)
f)\(\dfrac{11}{12}-\left(\dfrac{2}{5}+x\right)=\dfrac{2}{3}\)
g)\(\left|X+\dfrac{1}{3}\right|-4=\dfrac{-1}{2}\)
h)\(\left(\dfrac{1}{32}\right)^x.8^{2x}=512\)
i)\(5,3x+\left(-3,3\right)x+1,7=-4,9\)
2/3.x-3/2.(x-1/2)=5/12
1,5-2x.(-1 4/7)=11/4
1/1×2×3 + 1/2×3×4 + 1/3×4×5 + ... + 1/37×38×39
B1: thực hiên phép tinh a, (-2/3-1/6+1 ở giữa số 1/4)×(-36/20)=
B,(-10/15+1 ở giữa 1/6 -0,5)÷(4 ở giữa 4/105-54/81)=
B2: tìm x
A, 1/2x+4/5(2 ở giữa 1/2+x)=3 ở giữa 3/4
B, (3 ở giữa 1/3-2x)÷2 ở giữa 1/5=6 ở làm hộ
a,\(\dfrac{-4}{5}-\left(\dfrac{2}{3}x+1\dfrac{1}{4}\right)=\dfrac{2}{7}\)
b\(\dfrac{5}{6}+\left(\dfrac{3}{4}-\dfrac{1}{2}:x\right)=\dfrac{-2}{3}\)
c\(\left(\dfrac{4}{5}x-1\dfrac{1}{3}\right):\dfrac{3}{4}=0,7\)
d\(\dfrac{5}{6}-\dfrac{3}{4}x=1\dfrac{1}{3}+0,5x\)
giúp mình nhé mình đang cần gấp
Cho A =1/2^2+1/3^2+1/4^2+.....+1/99^2+1/100^2
