\(=\left(\frac{6}{12}+\frac{8}{12}-\frac{9}{12}\right).24\)
\(=\frac{6+8-9}{12}.24=\frac{5}{12}.24=10\)
\(=\left(\frac{6+8-9}{12}\right):\frac{1}{24}=\frac{5}{12}.24=10\)
Tính:
1/1×2×3+1/2×3×4+1/3×4×5+...+1/23×24×25
Tính giá trị biểu thức:
\(e,\dfrac{18}{37}+\dfrac{8}{24}+\dfrac{19}{37}-1\dfrac{23}{24}+\dfrac{2}{3}\)
\(f,\left(-2\right)^3.\left(\dfrac{3}{4}-0,25\right):\left(2\dfrac{1}{4}-1\dfrac{1}{6}\right)\)
\(g,\left(\dfrac{2}{5}\right)^2+5\dfrac{1}{2}.\left(4,5-2\right)+\dfrac{2^3}{\left(-4\right)}\)
\(h,\dfrac{4}{9}.19\dfrac{1}{3}-\dfrac{4}{9}.39\dfrac{1}{3}\)
\(i,\left(-\dfrac{1}{2}\right)^2:\dfrac{1}{4}-2\left(-\dfrac{1}{2}\right)^2\)
\(j,125\%.\left(\dfrac{-1}{2}\right)^2:\left(1\dfrac{5}{16}-1,5\right)+2008^0\)
\(k,\left(-2\right)^3.\dfrac{-1}{24}+\left(\dfrac{4}{3}-1\dfrac{5}{6}\right):\dfrac{5}{12}\)
Tính:
a) 16/15 . -5/14 . 54/24 . 56/21
b)7/3 . -5/2 . 15/21 . 4/-5
c)( -2/5 + 1/3) . ( 3/2 - 3/7)
d)(1/2 - 1/3) . ( 5 - 1/4)
e) ( 4/5)^2
Tìm x, biết: a) x = 1/4 + 5/13 b) x/3 = 2/3 + -1/7 c) x/3 = 16/24 + 24/ 36
d) x/15 = 1/5 + 2/3
Tập hợp các ước chung của 24 và 36 là
A 1 , 2 , 3 , 4 , 6 ,8 , 12
B 2, 3 , 4 , 6, 12 , 24
C 1 , 2 , 4 ,6 , 12
D 1 , 2 , 3 , 4 , 6 , 12
tìm x biết 1+1/30:(24+1/6-24+1/5)-(1+1/2-3/4)/(4x-1/2)=(-1+1/15):(8+1/5-8+1/3)
tìm x biết 1+1/30:(24+1/6-24+1/5)-(1+1/2-3/4)/(4x-1/2)=(-1+1/15):(8+1/5-8+1/3)
câu 1 2/8+2/24+2/48+2/80+2/120
câu 2 1/1*2+1/2*3+1/3*4+...+1/45*46
câu 3 4/1*3+4/3*5+4/5*7+...+4/51*53
a) -5/9 . 4/13+ -5/9. 9/13+2 và 5/9 ( 2 và 5/9 là hỗn số)
b) (-2)^3. -1/24+( 4/3- 1 và 5/6) : 3/14
c) 200 - (-100) -100+ (-20)
d) 15/34 +7/21 +19/34 -5/15 +3/7
e) (1-1/2) . (1-1/3). (1-1/4).....(1-1/1012)
g) (1/2+1/3-1/4) : 7/24
h) 15^20 . 9^10/ 27^12.25^10
