\(\dfrac{4}{9}+\dfrac{2}{9}+\dfrac{2}{9}=4\cdot\dfrac{1}{9}+2\cdot\dfrac{1}{9}+2\cdot\dfrac{1}{9}=\left(4+2+2\right)\cdot\dfrac{1}{9}=8\cdot\dfrac{1}{9}\Rightarrow x=8\)
\(\dfrac{4}{9}+\dfrac{5}{8}\)=
\(\dfrac{6}{10}+\dfrac{9}{2}=\)
\(\dfrac{10}{2}-\dfrac{5}{2}=\)
\(\dfrac{8}{8}x1=\)
Tính bằng cách thuận tiện
a. 5/7 x 5/9 + 4/9 x 5/7
b. 1/10 + 5/9 + 4/9 + 9/10 – 1
c. 5/7 x 5/9 + 4/9 x 5/7 + 2/7
d. 2/7 + 2/8 + 1/4 + 1/7 + 4/7
e. 4/5 + 3/10 + 2/10 + 0,7
f. 326 x 728 + 326 x 272
1+1+2+3+4+5+6+7+8++9+9+8+7+6+5+4+3+9+9+9+9+9+9+9+1+2+4+8+9+7+9+5+9+7+9+8+8+8
a+a x1/3:2/9+a:2/7=252
1/3 + 5/9 1/9 x 9/3
1/7 - 1/9 1/3 : 1/7
3 : 5/9 9 + 9/3
3 x 5/9 4 - 2/4
1 +1 +5 +6 + 9+ 2+ 3+ 5+ 6+ 5+ 9+ 5+ 3+ 2+ 8+ 1+ 5+ 5+ 9+ 9+ 8+ 8+ 8+ 8+ 8+ 8+ 6+ 3+ 3+ 3+ 2+ 1+ 1+ 1+5 +4 + 5+ 2+ 2
31 + 25+ 63+ 96+ 5+ 3+ 65+ 66+ 666+ 6+ 56+ 2+ 2+45 +5 + 5+ 456 +49 + 49+496+ 4554 +45 +562 +45 +693 +42+ 258 +6 +3 +3 +3 + 3+ 3+ 3+ 3+ 3+ 3+ 3+6 +6 + 6+ 6 +6 +6 + 6+ 6 +9 +9 + +9+ 9+ 9+9+6+9+9+9+9+9+9+9+9+9+9+9+9+9+9+9+9+9+9+ 9 + 9+ 9+9 + 9+ 9+ 9+ 9+ 9+ 9+ 9+ 9+9+9 + 9+9+ 9+ 9+ 9+9+9+ 9+ 9 + 9 +9 +9+9 + 9+ 9+9+ 9 + 9+ 9+ 9+ 9+ 9+ 9+ 9 +9 + 9 +9 +9 +9 + 9+ 9 +9 +9 + 9 +9 + 9+ 9+ 9 + =+ 9 +9 +9 +9 +9 + 9+ 9 + 9 + 9 + 9+ 9 + 9 + 9 + 9 +9 + 9+9 +9+9+ 9+ 9+ 9 +9++ 9 +9 + 9+9+9+9+9 ++9 + 9+9 + =
làm được minh tick cho
9/2 +9/4+9/8+....+9/128+9/256
a) 8/9 x 7/5 - 7/9 x 2/5 + 2/9
b) 5/9 x 1/4 + 4/9 x 3/12
tính nhanh, ghi cả lời nha
5 và 1/3+ 2 và 2/5 x1 và 1/9
