12/84+36/63=?( rút gọn rồi tính nhé)
Đặt tính rồi tính:
36 + 12 84 + 11 46 + 23
97 - 45 63 - 33 65 - 65
- Đặt tính: Viết các số cùng hàng thẳng cột với nhau.
- Tính: Lần lượt cộng hoặc trừ các số cùng hàng theo thứ tự từ phải sang trái.
Rút gọn rồi quy đồng mẫu các phân số sau:
a) 12/21, 4/56
b) 12/15, 6/36, 15/50
c) 63/77, 60/ 108, 18/-27
d) -26/-156, 49/-14, 32/112
a: 12/21=4/7=8/14
4/56=1/14
b: 12/15=4/5=24/30
6/36=1/6=5/30
15/50=3/10=9/30
c: 63/77=9/11=81/99
60/108=5/9=55/99
-18/27=-2/3=-66/99
d: -26/-156=1/6=7/42
49/-14=-7/2=-147/42
32/112=2/7=12/42
Rút gọn các phân số sau:
90/120 15/25 18/45 36/64 32/72 84/49
các bạn rút gọn hết cho mình nhé, nếu cảm thấy rút gọn đc nữa
\(\dfrac{90}{120}=\dfrac{30.3}{30.4}=\dfrac{3}{4}\)
\(\dfrac{15}{25}=\dfrac{5.3}{5.5}=\dfrac{3}{5}\)
\(\dfrac{18}{45}=\dfrac{9.2}{9.5}=\dfrac{2}{5}\)
\(\dfrac{36}{64}=\dfrac{4.9}{4.16}=\dfrac{9}{16}\)
\(\dfrac{32}{72}=\dfrac{8.4}{8.9}=\dfrac{4}{9}\)
\(\dfrac{84}{49}=\dfrac{7.12}{7.7}=\dfrac{12}{7}\)
\(\dfrac{90}{120}=\dfrac{3}{4};\dfrac{15}{25}=\dfrac{3}{5};\dfrac{18}{45}=\dfrac{2}{5};\dfrac{36}{64}=\dfrac{9}{16};\dfrac{32}{72}=\dfrac{4}{9};\dfrac{84}{49}=\dfrac{12}{7}\)
\(\dfrac{3}{4},\dfrac{3}{5},\dfrac{2}{5},\dfrac{9}{16},\dfrac{4}{9},\dfrac{12}{7}\)
Rút gọn rồi tính 5/15 + 48/16 6/9 : 12/36 4/12 × 56/14
\(\dfrac{5}{15}+\dfrac{48}{16}=\dfrac{1}{3}+3=\dfrac{1}{3}+\dfrac{9}{3}=\dfrac{10}{3}\)
\(\dfrac{6}{9}:\dfrac{12}{36}=\dfrac{2}{3}:\dfrac{1}{3}=\dfrac{2}{3}\times\dfrac{3}{1}=\dfrac{6}{3}=2\)
\(\dfrac{4}{12}\times\dfrac{56}{14}=\dfrac{1}{3}\times4=\dfrac{4}{3}\)
Rút gọn rồi tính:
\(\dfrac{20}{12}+\dfrac{36}{18}-\dfrac{21}{28}=?\)
Lời giải:
$\frac{20}{12}+\frac{36}{18}-\frac{21}{28}=\frac{5}{3}+2-\frac{3}{4}$
$=\frac{20}{12}+\frac{24}{12}-\frac{9}{12}=\frac{20+24-9}{12}=\frac{35}{12}$
\(=\dfrac{5}{3}+2-\dfrac{3}{4}=\dfrac{5.4+2.12-3.3}{12}=\dfrac{20+24-9}{12}=\dfrac{35}{12}\)
Rút gọn rồi tính:
18/27-2/6
15/25-3/21
24/36-6/12
a: =2/3-1/3=1/3
b: =3/5-1/7=21/35-5/35=16/35
c: =2/3-1/2=4/6-3/6=1/6
Rút gọn rồi tính: a)5/8+18/27 b)12/20+6/18 c)8/12+20/30 đ)10/12+12/36
b: 12/20+6/18=3/5+1/3=9/15+5/15=14/15
c: 8/12+20/30=2/3+2/3=4/3
d: 10/12+12/36=5/6+2/6=7/6
rút gọn rồi tính:
6/36 + 5/6
1/4 + 5/30
5/56 + 3/21
12/18 + 12/42
giúp ạ
\(\dfrac{6}{36}+\dfrac{5}{6}=\dfrac{1}{6}+\dfrac{5}{6}=\dfrac{6}{6}=1\\ \dfrac{1}{4}+\dfrac{5}{30}=\dfrac{1}{4}+\dfrac{1}{6}=\dfrac{6}{24}+\dfrac{4}{24}=\dfrac{10}{24}=\dfrac{5}{12}\\ \dfrac{5}{56}+\dfrac{3}{21}=\dfrac{5}{56}+\dfrac{1}{7}=\dfrac{5}{56}+\dfrac{8}{56}=\dfrac{13}{56}\\\dfrac{12}{18}+\dfrac{12}{42}=\dfrac{2}{3}+\dfrac{2}{7}=\dfrac{14}{21}+\dfrac{6}{21}=\dfrac{20}{21} \)
6/36 + 5/6=1/6+5/6=6/6=1
1/4 + 5/30=1/4+1/6=6/24+4/24=10/24=5/12
5/56 + 3/21=5/56=1/7=5/56+8/56=13/56
12/18 + 12/42=2/3+2/7=14/21+6/21=20/21
\(a,\dfrac{6}{36}+\dfrac{5}{6}=\dfrac{1}{6}+\dfrac{5}{6}=\dfrac{6}{6}=1\\ b,\dfrac{1}{4}+\dfrac{5}{30}=\dfrac{1}{4}+\dfrac{1}{6}=\dfrac{6}{24}+\dfrac{4}{24}=\dfrac{5}{12}\\ c,\dfrac{5}{56}+\dfrac{3}{21}=\dfrac{5}{56}+\dfrac{8}{56}=\dfrac{13}{56}\\ d,\dfrac{12}{18}+\dfrac{12}{42}=\dfrac{14}{21}+\dfrac{6}{21}=\dfrac{20}{21}\)
rút gọn rồi tính: a) \(\dfrac{15}{25}-\dfrac{3}{21}\) b) \(\dfrac{24}{36}-\dfrac{6}{12}\) AI ĐÚNG MÌNH TICK NHA
a, 15/25 - 3/21 = 3/5 - 1/7 = 21/35 - 5/35 = 18/35
b, 24/36 - 6/12 = 2/3 - 1/2 = 4/6 - 3/6 = 1/6
a)15/25-3/21=3/5-1/7=16/35 b)24/36-6/12=2/3-1/2=1/6