-3/8+5/12
8/9 - 2/6 + 5/12=
5/12 + 3/4 + 1/3=
1/12 + 5/6 + 3/8=
8/9 - 2/6 + 5/12 = 34/36 - 12/36 + 15/36= 35/36
5/12 + 3/4 + 1/3 = 5/12 + 9/12 + 4/12 = 3/2
1/12 + 5/6 + 3/8= 2/24 +20/24 +9/24 = 31/24
3/8 x 5/12 + 5/8 x 5/12
\(\dfrac{3}{8}\times\dfrac{5}{12}+\dfrac{5}{8}\times\dfrac{5}{12}\)
\(=\dfrac{5}{12}\times\left(\dfrac{3}{8}+\dfrac{5}{8}\right)\)
\(=\dfrac{5}{12}\times1\)
\(=\dfrac{5}{12}\)
3/8 x 5/12 + 5/8 x 5/12
= 5/12 x (3/8 + 5/8 )
= 5/12 x 1
= 5/12
\(\dfrac{3}{8}\times\dfrac{5}{12}+\dfrac{5}{8}\times\dfrac{5}{12}\)
\(=\dfrac{5}{12}\times\left(\dfrac{3}{8}+\dfrac{5}{8}\right)\)
\(=\dfrac{5}{12}\times1\)
\(=\dfrac{5}{12}\)
Tính nhẩm:
3 x 4 = 12 2 x 5 = 5 x 3 = 4 x 2 =
12 : 3 = 10 : 2 = 15 : 3 = 8 : 2 =
12 : 4 = 10 : 5 = 15 : 5 = 8 : 4 =
Ta tính nhẩm như sau:
3x4=12 2x5=10 5x3=15 4x2=8
12:3=4 10:2=5 15:3=5 8:2=4
12:4=3 10:5=2 15:5=3 8:4=2
3x4 = 12 2x5 = 10 5x3 = 15 4x2 =8
12 : 3 = 4 10 : 2 = 5 15 : 3 = 5 8 : 2 = 4
12 : 4 =3 10 :5 = 2 15 : 5 = 3 8 : 4 = 2
. Bài 3: Các phân số được xếp theo thứ tự lớn dần là: a. 1/2 ; 1/3 ; 3/8 ; 5/12
b. 1/3 ; 1/2; 5/12; 3/8
c. 1/3 ; 3/8 ; 5/12 ; 1/2
d. 3/8 ; 1/3 ; 1/2 ; 5/12
Tính nhẩm:
8 + 9 = ..... | 9 + 8 = ..... | 17 − 8 = ..... | 17 − 9 = ..... |
5 + 7 = ..... | 7 + 5 = ..... | 12 − 5 = ..... | 12 − 7 = ..... |
3 + 8 = ..... | 8 + 3 = ..... | 11 − 3 = ..... | 11 − 8 = ..... |
4 + 9 = ..... | 9 + 4 = ..... | 13 − 4 = ..... | 13 − 9 = ..... |
Phương pháp giải:
Tính nhẩm rồi điền số thích hợp vào chỗ trống.
Lời giải chi tiết:
8 + 9 = 17 | 9 + 8 = 17 | 17 − 8 = 9 | 17 − 9 = 7 |
5 + 7 = 12 | 7 + 5 = 12 | 12 − 5 = 7 | 12 − 7 = 5 |
3 + 8 = 11 | 8 + 3 = 11 | 11 − 3 = 8 | 11 − 8 = 3 |
4 + 9 = 13 | 9 + 4 = 13 | 13 − 4 = 9 | 13 − 9 = 4 |
8+9=17 9+8=17 17-8=9 17-9=8
5+7=12 7+5=12 12-5=7 17-7=5
Đúng ghi Đ sai ghi S
a) 3/8+4/8=7/8 b) 4/7+3/5 =7/12
c) 5/8+3/5=49/40 d) 2/3+3/4=17/12
[(3/8)-(3/10)-(3/11)-(3/12)]/(5/10-5/8-5/11-5/12
Giải đầy đủ nha
Tìm x biết :
1/-5 +(-3+12-x)=7-(2-8)
2/8-(7-x+3)=-|-7+2|-(-9)
3/-(12-5+9-x)=3-|5-8+2|
4/-(-3-x+8)-(-3+5)=|5-8|
5/-|5-8|-(4-x+5)=4+|3-9|
mình đang cần gấp câu trả lời ,bạn nào giải được nhanh k luôn ,hứa đấy
1) -5+(-3+12-x)=7-(2-8)
=>-5+(9-x)=7-(-6)
=>-5+9-x=13
=>x=9-5-13=-9
2) 8-(7-x+3)=-|-7+2|-(-9)
=>8-(10-x)=-|-5|+9
=>8-10+x=-5+9
=>x=-5+9-8+10=6
3)-(12-5+9-x)=3-|5-8+2|
=>-(16-x)=3-|-1|
=>-16+x=3-1
=>x=3-1+16=18
4)-(-3-x+8)-(-3+5)=|5-8|
=>-(5-x)-2=|-3|
=>-5+x-2=3
=>x=3+5+2=10
5)-|5-8|-(4-x+5)=4+|3-9|
=>-|-3|-(9-x)=4+|-6|
=>-3-9+x=4+6
=>x=4+6+3+9=22
\(\dfrac{\dfrac{3}{8}-\dfrac{3}{10}+\dfrac{3}{11}+\dfrac{3}{12}}{-\dfrac{5}{8}+\dfrac{5}{10}-\dfrac{5}{11}-\dfrac{5}{12}}\)
A = \(\dfrac{\dfrac{3}{8}-\dfrac{3}{10}+\dfrac{3}{11}+\dfrac{3}{12}}{-\dfrac{5}{8}+\dfrac{5}{10}-\dfrac{5}{11}-\dfrac{5}{12}}\)
A = \(\dfrac{3.\left(\dfrac{1}{8}-\dfrac{1}{10}+\dfrac{1}{11}+\dfrac{1}{12}\right)}{-5.\left(\dfrac{1}{8}-\dfrac{1}{10}+\dfrac{1}{11}+\dfrac{1}{12}\right)}\)
A = - \(\dfrac{3}{5}\)