\(\frac12+\frac52=\frac{1+5}{2}=\frac62=3\)
\(\frac12+\frac52\) \(=\frac{1+5}{2}\) \(=\frac62=\frac31=3\)
Tính Nhanh
a) ( 1/2 + 1/3 + 1/4 + 1/5 + 1/6 ) - ( 1/2 + 1/3 + 1/4 + 1/5 )
b) ( 2/3 + 2/4 + 2/5 + 2/6 + 2/7 ) - ( 2/4 + 2/5 + 2/6 + 2/7 + 28 )
bài 1:
1/4 + 2/3 2/7 + 2/3 2/5 + 1/3 2/3 + 1/2 1/3 + 3/5 4/5 + 1/3
1/8 + 3/4 1/36 + 5/12 1/3 + 1/6 + 1/18.
bài 2:
15/16 - 3/16 17/18 - 5/6 3/4 - 4/9 1/2 - 2/5 5/6 - 3/10 3-1/3
4/5 - 1/10 5/2 - 1 5/8 - 2/5.
Các phân số 1/3: 1/6: 5/2: 3/2 xếp theo thứ tự tăng dần
a. 1/3; 1/6; 5/2; 3/2 b. 1/3; 5/2; 1/6; 3/2 c. 1/6; 1/3; 3/2; 5/2 d. 1/6; 3/2; 3/2; 5/2
Tính bằng cách thuận tiện nhất:
2/5 x 5 +4 x 2/5+2/5 (1-1/2)x(1-3/5)x(1-2/7)x(1-2/9)
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2/5x5+4x2/5+2/5 (1-1/2)x(1-3/5)x(1-2/7)x(1-2/9)
2/5x5+4x2/5+2/5 (1-1/2)x(1-3/5)x(1-2/7)x(1-2/9)
1) 1/3 x 1/2 x 3/7 2) 5/4 x 1/3 + 1/7 3) 8 x ( 8/9-2/3 ) 4) 5/6 x 48/20 x 1/2 5) ( 2/5 + 3/4 ) x 8 6) 10 x ( 1/2-1/5 )
1/2+{1/3+2/3}+{1/4+2/4+3/4}+1/5+2/5+3/5+4/5}
35 nhan x + 1/2 : 5/3 - 5/4 = 1/2 x 1/3
3/5 nhan x + 1/2 : 5/3 - 5/4 = 1/2 x 1/3
2/3+5/2-3/4=
2/5*1/2/1/3=
2/9/2/9/1/2=
4/5-1/2+1/3=
1/2*1/3+1/4=
2/7/2/3-1/7=
