bt 1:thực hiện phép tính
a) 13/25 + 6/41-38/25+35/41-1/2
b)3 1/4.17 3/47-3 1/4.3 3/47
c)0,5.V100-V81
a) 21/47 + 9/45 +26/47 + 4/5
= (21/47 + 26/47) + (9/45 + 4/5)
=1+1 = 2
b) 15/12 + 5/13 - 3/12 - 18/13
= (15/12 - 3/12) + (18/13 - 5/13)
=1+1 = 2
c) 13/25 + 6/41 - 38/25 + 35/41 - 1/2
= (38/25 - 13/25) + (35/41 + 6/41) + 1/2
= 1+1 + 1/2 = 5/2
d) 27/23 + 5/21 - 4/23 + 6/21 + 1/2
= (27/23 - 4/23) + (6/21 - 5/21) + 1/2
= ..........................
Đúng không? Phần sau mình tính sao ra kết quả lạ lắm, tính giúp mình.
(-3/4+2/3):5/11+(-1/4+1/3):5/11
a)|x-13|-35-45=-47
b)(4+x).(x+3)=0
c)25-(5-x)=120-(28-5)
28) 15/12+5/13-3/12-18/13
29) 13/25+6/41-38/25+35/41-1/2
30
Thực hiện phép tính ( tính hợp lí nếu có thể )
a)\(\frac{1}{5}+\frac{-2}{3}\)
b)\(\frac{15}{12}+\frac{5}{13}-\frac{3}{12}-\frac{18}{13}\)
c) \(\frac{13}{25}+\frac{6}{41}-\frac{38}{25}+\frac{35}{41}-\frac{1}{2}\)
d)\(\frac{5}{6}.18\frac{2}{3}-\frac{5}{6}.6\frac{2}{3}\)
Mấy bạn làm được câu nào thì làm nha! THANKS
\(a.=\frac{3}{15}+\frac{-10}{15}\)
\(=-\frac{7}{15}\)
\(b.=\left(\frac{15}{12}-\frac{3}{12}\right)+\left(\frac{5}{13}-\frac{18}{13}\right)\)
\(=1+\left(-1\right)\)
\(=0\)
\(c.=\left(\frac{13}{25}-\frac{38}{25}\right)+\left(\frac{6}{41}+\frac{35}{41}\right)-\frac{1}{2}\)
\(=-1+1-\frac{1}{2}\)
\(=0-\frac{1}{2}\)
\(=-\frac{1}{2}\)
\(d.=\frac{5}{6}.\left(18\frac{2}{3}-6\frac{2}{3}\right)\)
\(=\frac{5}{6}.12\)
\(=10\)
a)1/5+-2/3
=3/15+-10/15
=-7/15
b)15/12+5/13-3/12-18/13
=(15/12-3/12)+(5/13-18/13)
=1+-1
=0
c)13/25+6/41-38/25+35/41-1/2
=(13/25-38/25)+(6/41+35/41)-1/2
=1+1-1/2
=2-1/2
=2/2-1/2
=1/2
d)5/16x18’2/3-5/6x6’2/3
=5/16x(18’2/3-6’2/3)
=5/16x12
=15/4
Chúc bạn hok tốt😄😄
Thực hiện các phép tính sau ( tính hợp lí nếu có thể):
a,2/9-(1/20+2/9) b,-3/14+2/13+(-25)/14+(-15)/13
c,(-3/11)+11/8-3/8+(-8/11) d, 3/8+(-1)/4-(7/12-1/6)
e, (1/3+12/67+13/41)-(79/67-28/41)
a) 2/9 - (1/20 + 2/9)
= 2/9 - 1/20 - 2/9
= (2/9 - 2/9) - 1/20
= 0 - 1/20
= -1/20
b) -3/14 + 2/13 + (-25/14) + (-15/13)
= (-3/14 - 25/14) + (2/13 - 15/13)
= -2 - 1
= -3
c) -3/11 + 11/8 - 3/8 + (-8/11)
= (-3/11 - 8/11) + (11/8 - 3/8)
= -1 + 1
= 0
d) 3/8 + (-1/4) - (7/12 - 1/6)
= 1/8 - 5/12
= -7/24
e) (1/3 + 12/67 + 13/41) - (79/67 - 28/41)
= 1/3 + 12/67 + 13/41 - 79/67 + 28/41
= 1/3 + (12/67 - 79/67) + (13/41 + 28/41)
= 1/3 - 1 + 1
= 1/3
13/25+6/41−38/25+35/41−1/2
a)\(\frac{15}{12}+\frac{5}{13}-\frac{3}{12}-\frac{18}{13}\)
b)\(\frac{11}{24}-\frac{5}{41}+\frac{13}{24}+0,5-\frac{36}{41}\)
c)\(\left(-\frac{3}{4}+\frac{2}{3}\right):\frac{5}{11}+\left(-\frac{1}{4}+\frac{1}{3}\right):\frac{5}{11}\)
d)\(\left(-3\right)^2\cdot\left(\frac{3}{4}-0,25\right)-\left(3\frac{1}{2}-1\frac{1}{2}\right)\)
e)\(\frac{13}{25}+\frac{6}{41}-\frac{38}{25}+\frac{35}{41}-\frac{1}{2}\)
a) \(\frac{15}{12}+\frac{5}{13}-\frac{3}{12}-\frac{18}{13}=\left(\frac{15}{12}-\frac{3}{12}\right)+\left(\frac{5}{13}-\frac{18}{13}\right)\)
\(=1+\left(-1\right)\)
\(=0\)
b) \(\frac{11}{24}-\frac{5}{41}+\frac{13}{24}+0,5-\frac{36}{41}=\left(\frac{11}{24}+\frac{13}{24}\right)+\left(-\frac{5}{41}-\frac{36}{41}\right)+0,5\)
\(=1+\left(-1\right)+0,5\)
\(=0,5\)
_Học tốt nha_
a, \(\frac{15}{12}\)+ \(\frac{5}{13}\)- \(\frac{3}{12}\)-\(\frac{18}{13}\)
= \(\frac{5}{4}\)+ \(\frac{5}{13}\) - \(\frac{1}{4}\) - \(\frac{18}{13}\)
= \(\left(\frac{5}{4}-\frac{1}{4}\right)\)+ \(\left(\frac{5}{13}-\frac{18}{13}\right)\)
= 1 - 1 = 0
b, \(\frac{11}{24}\)- \(\frac{5}{41}\)+ \(\frac{13}{24}\)+ 0,5 - \(\frac{36}{41}\)
= \(\left(\frac{11}{24}+\frac{13}{24}\right)\)- \(\left(\frac{5}{41}+\frac{36}{41}\right)\)+ 0,5
= 1 - 1 + 0,5 = 0,5
c, \(\left(-\frac{3}{4}+\frac{2}{3}\right):\frac{5}{11}+\left(-\frac{1}{4}+\frac{1}{3}\right):\frac{5}{11}\)
=\(\left(-\frac{3}{4}+\frac{2}{3}\right).\frac{11}{5}+\left(-\frac{1}{4}+\frac{1}{3}\right).\frac{5}{11}\)
= \(\frac{11}{5}.\left(-\frac{3}{4}+\frac{2}{3}-\frac{1}{4}+\frac{1}{3}\right)\)
= \(\frac{11}{5}.\left[\left(-\frac{3}{4}-\frac{1}{4}\right)+\left(\frac{2}{3}+\frac{1}{3}\right)\right]\)
= \(\frac{11}{5}.\left[\left(-1\right)+1\right]\)
= 0
d, \(\left(-3\right)^2.\left(\frac{3}{4}-0,25\right)-\left(3\frac{1}{2}-1\frac{1}{2}\right)\)
= \(9.\left(0,75-0,25\right)-2\)
= 9. 0,5 - 2 = 2,5
e, \(\frac{13}{25}+\frac{6}{41}-\frac{38}{25}+\frac{35}{41}-\frac{1}{2}\)
= \(\left(\frac{13}{25}-\frac{38}{25}\right)+\left(\frac{6}{41}+\frac{35}{41}\right)-\frac{1}{2}\)
= -1 + 1 - \(\frac{1}{2}\)
= \(-\frac{1}{2}\)
a) 15/12 + 5/13- 3/12 - 18/13 = (15/12 - 3/12) + ( 5/13 - 18/13) = 12/12 + -13/13 = 1 + (-1) = 0
b) 11/24 - 5/41 + 13/24 + 0,5 - 36/41 = (11/24 +13/24) - (5/41+36/41)+0,5 = 1 - 1+0,5 = 0,5
c) ( -3/4 + 2/3) : 5/11 + (-1/4 + 1/3 ) : 5/11 = -3/4 + 2/3 : 5/11 + -1/4 + 1/3 = = [( -3/4 + (-1/4) ] + ( 2/3 + 1/3) : 5/11
= -4/4 + 3/3 : 5/11 = -1 + 1 * 11/5
= 0 * 11/5 = 0
d) (-3) ^2 * (3/4 - 0,25) - ( 3 1/2 - 1 1/2) = 9 * (3/4 - 25/100) - ( 7/2 -3/2) = 9 * ( 3/4 - 1/4) - 4/2
= 9* 1/2 - 2 = 9/ 2 - 2= 5/2
e) 13/25 + 6/41 - 38/25 + 35/41 - 1/2 = ( 13/25 - 38/25) + ( 6/41 + 35/41) - 1/2 = -25/25 + 41/41 - 1/2 = (-1) + 1 - 1/2 = 0 - 1/2 = -1/2
\(\frac{13}{25}+\frac{6}{41}-\frac{38}{25}+\frac{35}{41}-\frac{1}{2}\)
\(1\frac{4}{23}+\frac{5}{21}-\frac{4}{23}+0,5+\frac{16}{21}\)
\(\frac{13}{25}+\frac{6}{41}-\frac{38}{25}+\frac{35}{41}-\frac{1}{2}\)
\(=\left(\frac{13}{25}-\frac{38}{25}\right)+\left(\frac{6}{41}+\frac{35}{41}\right)-\frac{1}{2}\)
\(=-1+1-\frac{1}{2}=0-\frac{1}{2}\)
\(=\frac{-1}{2}\)
\(1\frac{4}{23}+\frac{5}{21}-\frac{4}{23}+0,5+\frac{16}{21}\)
\(=\left(1\frac{4}{23}-\frac{4}{23}\right)+\left(\frac{5}{21}+\frac{16}{21}\right)+0,5\)
\(=1+1+0,5=2,5\)
\(\frac{13}{25}+\frac{4}{41}-\frac{38}{25}+\frac{35}{41}-\frac{1}{2}\)
= \(\left(\frac{13}{25}-\frac{38}{25}\right)+\left(\frac{6}{41}+\frac{35}{41}\right)-\frac{1}{2}\)
= \(-1+1-\frac{1}{2}=-\frac{1}{2}\)
\(1\frac{4}{23}+\frac{5}{21}-\frac{4}{23}+0,5+\frac{16}{21}\)
=\(\left(1\frac{4}{23}-\frac{4}{23}\right)+\left(\frac{5}{21}+\frac{16}{21}\right)+0,5\)
= \(1+1+0,5=2,5\)
Bài 1: Thực hiện phép tính:
1, 4/23 + 5/21 + 0,5 - 4/23 + 16/21
2, (1/3 + 12/67 + 13/41)-(79/67 - 28/41)
3, 12,5 x (-5/7)+1,5 x (-5/7)
4, 3/8x19 1/3- 3/8x33 1/3
5, 5/7x(-3/11)+5/7x(-8/11)+2 5/7
6, (-5/11:13/8-5/11:13/5)- giá trị tuyệt đối của -1/33
1: \(\dfrac{4}{23}+\dfrac{5}{21}+\dfrac{1}{2}-\dfrac{4}{23}+\dfrac{16}{21}\)
\(=1+\dfrac{1}{2}\)
\(=\dfrac{3}{2}\)
2: \(\left(\dfrac{1}{3}+\dfrac{12}{67}+\dfrac{13}{41}\right)-\left(\dfrac{79}{67}-\dfrac{28}{41}\right)\)
\(=\dfrac{1}{3}+\dfrac{12}{67}+\dfrac{13}{41}-\dfrac{79}{67}+\dfrac{28}{41}\)
\(=\dfrac{1}{3}\)
Tính bằng cách hợp lí:
a) \(\frac{15}{12}+\frac{5}{13}-\frac{3}{12}-\frac{18}{13}\) ( Phép này tính bằng 1 nhưng lại sai mất)
b) \(\frac{13}{25}+\frac{6}{41}-\frac{38}{25}+\frac{35}{41}-\frac{1}{2}\)
c) \(\left(\frac{1}{2}-\frac{2}{3}\right)-\left(\frac{5}{3}-\frac{3}{2}\right)+\left(\frac{7}{3}-\frac{5}{2}\right)\)
Help me!!!!! Nhanh nhé, 15' thui
\(a,=\left(\frac{15}{12}-\frac{3}{12}\right)+\left(\frac{5}{13}-\frac{18}{13}\right)\)
\(=1+-1\)
\(=0\)