\(\dfrac{9}{8}\):\(\dfrac{3}{7}\)=\(\dfrac{21}{8}\)
\(\dfrac{9}{8}:\dfrac{3}{7}=\dfrac{9}{7}\times\dfrac{7}{3}=\dfrac{9\times7}{7\times3}=3\)
1+2+3+4+5+6+7+8+9+1+2+3+4+5+6+7+8+9+1+2+3+4+5+6+7+8+9=?
3/8......3/5
6/7.......7/8
9/5......3/4
8/9.......4/9
8/9 + 3/18 ; 5/7 - 4/11 ; 7/9 x 3/4 ; 12/7 : 1/4
3/4 + 4/5 ; 5/7 - 3/5 ; 8/3 x 21/4 ; 7/2 : 9/4
Chọn phép tính đúng:
A 1/2×1/2=1×1 2×2=1/4
B 3/5×4/9=3×9 5×4=2720
C 5/3×3/7=3×3 5×7=935
D 7/9×3/8=7×3/ 9×8=724
1+1+1+2+2+2+3+3+3+4+4+4+5+5+5+6+6+6+7+7+7+8+8+8+9+9+9+.......+n
Tìm n
Tính nhanh các biểu thức sau :
a) (45 – 5 x 9) x 1 x 2 x 3 x 4 x 5 x 6 x 7
b) (1 + 2 + 3 + 4 + 5 + 6 + 7 + 8 + 9 + 10) x (72 – 8 x 8 – 8)
c) (36 – 4 x 9) : (3 x 5 x 7 x 9 x 11)
d) (27 – 3 x 9) : 9 x 1 x 3 x 5 x 7
2. Tính bằng hai cách: A) ( 7/9 + 3/5 ) x 2/3. B) ( 9/11 - 3/11 ) x 5/7. C) 7/8 x ( 8/9 - 1/3 ).
2. Tính bằng hai cách: A) ( 7/9 + 3/5 ) x 2/3. B) ( 9/11 - 3/11 ) x 5/7. C) 7/8 x ( 8/9 - 1/3 ).
A,\(\dfrac{8}{9}:\dfrac{4}{5}+\dfrac{3}{5}\)
B,\(\dfrac{5}{8}\) + \(\dfrac{1}{4}\)
C,\(\dfrac{7}{8}\) x \(\dfrac{4}{7}\) +\(\dfrac{5}{9}\)
D,\(\dfrac{9}{8}:\dfrac{4}{3}-\dfrac{4}{7}\)
Tính bằng cách thuận tiện nhất:
2/7 + 3/5 + 3/8 + 1/9 + 4/8 + 2/5 + 8/9 + 1/8 + 5/7
