Tính giá trị biểu thức:
a) 1/3 + 1/6 *4
b)11/3 + 1/6 * 2/5 - 2
Tính giá trị của biểu thức:
a)2 3/5+1 2/5x31/2 b)4 3/4-3 2/3:1 1/6
a: \(2\dfrac{3}{5}+1\dfrac{2}{5}\cdot\dfrac{31}{2}\)
\(=\dfrac{13}{5}+\dfrac{7}{5}\cdot\dfrac{31}{2}\)
\(=\dfrac{26}{10}+\dfrac{217}{10}=\dfrac{243}{10}\)
b: \(4\dfrac{3}{4}-3\dfrac{2}{3}:1\dfrac{1}{6}\)
\(=\dfrac{19}{4}-\dfrac{11}{3}:\dfrac{7}{6}\)
\(=\dfrac{19}{4}-\dfrac{11}{3}\cdot\dfrac{6}{7}\)
\(=\dfrac{19}{4}-\dfrac{22}{7}\)
\(=\dfrac{19\cdot7-22\cdot4}{28}=\dfrac{45}{28}\)
Tính nhanh giá trị biểu thức:
A = (1/33 - 13/55 + 17/777) . (1/2 + 1/3 - 5/6)
Tính giá trị biểu thức:
A= 1-2-3+4+5-6-7+...+2021-2022-2023
=(1-2-3+4)+(5-6-7+8)+...+(2017-2018-2019+2020)+2021-2022-2023
=0+0+...+0-1-2023
=-2024
Câu 3 Tính giá trị biểu thức:
a)5/3+4/9:1/2 b)11/10-2/5:2/3
Câu 4.Tính nhanh
12x15x20 / 10x16x25
Mik cần gấp
a) \(\dfrac{5}{3}+\dfrac{4}{9}:\dfrac{1}{2}=\dfrac{5}{3}+\dfrac{4}{9}\times2=\dfrac{5}{3}+\dfrac{8}{9}=\dfrac{23}{9}\)
b) \(\dfrac{11}{10}-\dfrac{2}{5}:\dfrac{2}{3}=\dfrac{11}{10}-\dfrac{2}{5}\times\dfrac{3}{2}=\dfrac{11}{10}-\dfrac{3}{5}=\dfrac{11}{10}-\dfrac{6}{10}=\dfrac{5}{10}=\dfrac{1}{2}\)
Câu 4
\(\dfrac{12\times15\times20}{10\times16\times25}=\dfrac{3\times4\times3\times5\times4\times5}{5\times2\times4\times4\times5\times5}=\dfrac{3\times3}{5\times2}=\dfrac{9}{10}\)
Câu 3:
\(a.\dfrac{5}{3}+\dfrac{4}{9}:\dfrac{1}{2}=\dfrac{5}{3}+\dfrac{8}{9}=\dfrac{15}{9}+\dfrac{8}{9}=\dfrac{23}{9}\)
\(b.\dfrac{11}{10}-\dfrac{2}{5}:\dfrac{2}{3}=\dfrac{11}{10}-\dfrac{3}{5}=\dfrac{11}{10}-\dfrac{6}{10}=\dfrac{5}{10}=\dfrac{1}{2}\)
Câu 4:
\(\dfrac{12\times15\times20}{10\times16\times25}=\dfrac{3\times3\times1}{2\times1\times5}=\dfrac{9}{10}\)
* Tính giá trị của biểu thức:
a. A=\(2\sqrt{2}-3\sqrt{18}+4\sqrt{32}-\sqrt{50}\)
b. B=\(\sqrt{\left(1-\sqrt{5}\right)^2}+\sqrt{6+2\sqrt{5}}\)
c. C=\(\dfrac{1}{2-\sqrt{6}}+\dfrac{1}{2+\sqrt{6}}\)
\(a,A=2\sqrt{2}-9\sqrt{2}+16\sqrt{2}-5\sqrt{2}\)
\(=4\sqrt{2}\)
\(b,B=\left|1-\sqrt{5}\right|+\sqrt{5+2\sqrt{5}+1}\)
\(=\left|1-\sqrt{5}\right|+\sqrt{\left(\sqrt{5}+1\right)^2}\)
\(=\left|1-\sqrt{5}\right|+\left|\sqrt{5}+1\right|=\sqrt{5}-1+\sqrt{5}+1=2\sqrt{5}\)
\(c,C=\dfrac{2+\sqrt{6}+2-\sqrt{6}}{\left(2+\sqrt{6}\right)\left(2-\sqrt{6}\right)}=\dfrac{4}{4-6}=-2\)
Lời giải:
a.
\(A=2\sqrt{2}-3\sqrt{18}+4\sqrt{32}-\sqrt{50}=2\sqrt{2}-9\sqrt{2}+16\sqrt{2}-5\sqrt{2}\)
\(=(2-9+16-5)\sqrt{2}=4\sqrt{2}\)
b.
\(B=\sqrt{(1-\sqrt{5})^2}+\sqrt{(\sqrt{5}+1)^2}=|1-\sqrt{5}|+|\sqrt{5}+1|=\sqrt{5}-1+\sqrt{5}+1=2\sqrt{5}\)
c.
\(C=\frac{2+\sqrt{6}+2-\sqrt{6}}{(2-\sqrt{6})(2+\sqrt{6})}=\frac{4}{2^2-6}=-2\)
`a)A=2sqrt2-3sqrt{18}+4sqrt{32}-sqrt{50}`
`=2sqrt2-3sqrt{9.2}+4sqrt{16.2}-sqrt{25.2}`
`=2sqrt2-9sqrt2+16sqrt2-5sqrt2`
`=4sqrt2`
`b)B=sqrt{(1-sqrt5)^2}+sqrt{6+2sqrt5}`
`=sqrt5-1+sqrt{(sqrt5+1)^2}`
`=sqrt5-1+sqrt5+1=2sqrt5`
`c)1/(2-sqrt6)+1/(2+sqrt6)`
`=(2+sqrt6)/(4-6)+(sqrt6-2)/(6-4)`
`=(sqrt6-2-sqrt6-2)/2=-2`
Tính giá trị của biểu thức:A=(2 và 1/3+3,5):(-4 và 1/6+2 và 1/7)+7,5
Tính giá trị biểu thức:
a) 6 : 5/2 - 3/10
b) 4/6 : 4/3 + 5 : 4/3
a. 7/2 - 3/10 = 16/5
b. (4/6 + 5):4/3=17/3 :4/3=17/4
a) \(6-\dfrac{5}{2}-\dfrac{3}{10}=\dfrac{7}{2}-\dfrac{3}{10}=\dfrac{16}{5}\)
b) \(\dfrac{4}{6}\div\dfrac{4}{3}+5\div\dfrac{4}{3}\)
\(=\dfrac{1}{2}+\dfrac{15}{4}\)
\(=\dfrac{17}{4}\)
Tính giá trị của biểu thức:
a, 6 : 5/2 - 3/10
b, 4/6 : 4/3 + 5 : 4/3
a) 6/1x 2/5-3/10
= 12/5- 3/10
= 21/10
b) (4/6+5):4/3
= 17/3x 3/4
= 17/4
a) 6 : 5/2 - 3/10 = 12/5 - 3/10 = 21/10
b) 4/6 : 4/3 + 5 : 4/3 = 1/2 + 5 : 4/3 = 1/2 + 15 /4 = 17/4
Tính giá trị của biểu thức:
a, 6 : 5/2 - 3/10
b, 4/6 : 4/3 + 5 : 4/3
a)
`6:5/2-3/10`
`=6xx2/5-3/10`
`=12/5-3/10`
`=24/10-3/10`
`=21/10`
b)
`4/6:4/3+5:4/3`
`=2/3xx3/4+5xx3/4`
`=3/4xx(2/3+5)`
`=3/4xx(2/3+15/3)`
`=3/4xx17/3`
`=17/4`
\(a,6:\dfrac{5}{2}-\dfrac{3}{10}\\ =\dfrac{6}{1}:\dfrac{5}{2}-\dfrac{3}{10}\\ =\dfrac{6}{1}\times\dfrac{5}{2}-\dfrac{3}{10}\\ =\dfrac{12}{5}-\dfrac{3}{10}\\ =\dfrac{12\times2}{5\times2}-\dfrac{3}{10}\\ =\dfrac{24}{10}-\dfrac{3}{10}\\ =\dfrac{21}{10}\)
\(b,\dfrac{4}{6}:\dfrac{4}{3}+5:\dfrac{4}{3}\\ =\dfrac{4}{6}:\dfrac{4}{3}+\dfrac{5}{1}:\dfrac{4}{3}\\ =\dfrac{4}{3}:\left(\dfrac{4}{6}+\dfrac{5}{1}\right)\\ =\dfrac{4}{3}:\left(\dfrac{4}{6}+\dfrac{5\times6}{1\times6}\right)\\ =\dfrac{4}{3}:\left(\dfrac{4}{6}+\dfrac{30}{6}\right)\\ =\dfrac{4}{3}:\dfrac{34}{6}\\ =\dfrac{4}{3}:\dfrac{17}{3}\\ =\dfrac{4}{3}\times\dfrac{3}{17}\\=\dfrac{12}{51} \\ =\dfrac{4}{17}.\)
\(a,6:\dfrac{5}{2}-\dfrac{3}{10}=6\times\dfrac{5}{2}-\dfrac{3}{10}=\dfrac{12}{5}-\dfrac{3}{10}=\dfrac{24}{10}-\dfrac{3}{10}=\dfrac{21}{10}\)
\(b,\dfrac{4}{6}:\dfrac{4}{3}+5:\dfrac{4}{3}=\dfrac{4}{6}\times\dfrac{3}{4}+5\times\dfrac{3}{4}=\dfrac{2}{4}+\dfrac{15}{4}=\dfrac{17}{4}\)
Tính giá trị của biểu thức:
a/ 35 – 2.1111 + 3. 72
b/ 5.43 + 2.3 – 81. 2 + 7
c/ 25 + 2.{12 + 2.[3.(5-2)+1]+1}+1
d/ 17.131 + 69.17
e/ 50 – [30 - (6 - 2)2 ]
f/ 199 +36 + 201 + 184 + 37
a/ 35 – 2.1111 + 3. 72
= 35 - 2.1 + 3.49
= 35 - 2 + 147
= 33 + 147
= 180
b/ 5.43 + 2.3 – 81. 2 + 7
= 5.64 + 6 - 162 + 7
= 320 + 6 - 162 + 7
= 326 - 162 + 7
= 164 + 7
= 171
c/ 25 + 2.{12 + 2.[3.(5-2)+1]+1}+1
= 32 + 2.{12 + 2.[3.3+1]+1}+1
= 32 + 2.{12 + 2.10+1}+1
= 32 + 2.{12 + 20 + 1}+1
= 32 + 2.{32+1}+1
= 32 + 2.33 + 1
= 32 + 66 + 1
= 98 + 1
= 99
d/ 17.131 + 69.17
= 17 . (131+69)
= 17 . 200
= 3400
e/ 50 – [30 - (6 - 2)2 ]
= 50 - [30 - 42]
= 50 - 14
= 36
f/ 199 +36 + 201 + 184 + 37
= (199+201)+(36+184)+37
= 400 + 220 + 37
= 657