Thuc hien phep tinh :
-4/7 . 2/5 + 6/7 . -3/10
Help me !!!! Thanks
thuc hien phep tinh
( 5*4^15*9-4*3^20*8^9) /( 5*2^9*6^19-7*2^29*27^6)
Tách hai dấu ngoặc thành hai vế A và B
Ta có :
A=5.415.99-4.320.89=5.230.318-22.227.320
=229.318(2.5-32)=229.318
B=5.29.619-7.229.276=5.29.219.319-7.229.318
=228.318(5.3-7.2)=228.318
=>A:B=229.318:228:318=2
thuc hien cac phep tinh
1-2-3+4+5-6-7+...+2001-2002-2003+2004
Thuc hien cac phep tinh sau ;a] [5/6 + 6/9 ] * 3/11
b] [ 7/6 - 1/4 ] \ 3/4
Thuc hien phep tinh \(\frac{5}{4-\sqrt{11}}+\frac{1}{3+\sqrt{7}}-\frac{6}{\sqrt{7}-2}-\frac{\sqrt{7}-5}{2}\)
thuc hien phep tinh (Tinh nhanh neu co the)
(-5/12+7/4-3/8)-|4 va 1/2 -7 va 1/2|-( 1/4-5/2)
Thuc hien phep tinh
A, 3/7 + 1/2 - (-3)/70
B, 3/5 + -1/25 - 35/100
C, 5/12 - 3/-16 + 3/4
D, 5/15 + 4/-12 + 1/7 - 1/-6
a,3/7 +1/2-[-3]/70
=13/14 -[-3]/70
=65/70 -[-3]/70
=34/35
b,3/5+-1/25 -35/100
=14/25 - 35/100
=56 /100 -35/100
= 21/100
c ,5/12 -3/-16+3/4
=29/48 +3/4
= 29/48 +36/48
=65/48
d, 5/15 +4/-12 +1/7 -1/-6
= 1/3 +1/-3 +1/7-1/-6
=0+1/7-1/-6
= 13/42
A.\(\dfrac{3}{7}+\dfrac{1}{2}+\dfrac{\left(-3\right)}{70}\)
=\([\dfrac{30}{70}+\dfrac{\left(-3\right)}{70}]\)+\(\dfrac{1}{2}\)
= \(\dfrac{27}{70}+\dfrac{35}{70}\)
=\(\dfrac{62}{70}=\dfrac{31}{35}\)
B.\(\dfrac{3}{5}+\dfrac{-1}{25}-\dfrac{35}{100}\)
=\(\dfrac{60}{100}+\dfrac{-4}{100}-\dfrac{35}{100}\)
=\(\dfrac{60+\left(-4\right)-35}{100}\)
=\(\dfrac{21}{100}\)
C.\(\dfrac{5}{12}-\dfrac{3}{-16}+\dfrac{3}{4}\)
=\(\left(\dfrac{5}{12}+\dfrac{9}{12}\right)-\dfrac{-3}{16}\)
=\(\dfrac{7}{6}-\dfrac{-3}{16}\)
=\(\dfrac{56}{48}-\dfrac{-9}{48}\)=\(\dfrac{65}{48}\)
D.\(\dfrac{5}{15}+\dfrac{4}{-12}+\dfrac{1}{7}-\dfrac{1}{-6}\)
=\(\dfrac{1}{3}+\dfrac{1}{7}+(\dfrac{-2}{6}-\dfrac{-1}{6})\)
=\(\dfrac{1}{3}+\dfrac{1}{7}+\dfrac{-1}{6}\)
=\((\dfrac{1}{3}+\dfrac{-1}{6})+\dfrac{1}{7}\)
=\(\dfrac{1}{6}+\dfrac{1}{7}\)=\(\dfrac{13}{42}\)
thuc hien phep tinh
\(\frac{6}{7}+\frac{1}{7}.\frac{2}{7}+\frac{1}{7}.\frac{5}{7}\)
\(\frac{6}{7}+\frac{1}{7}.\frac{2}{7}+\frac{1}{7}.\frac{5}{7}=\frac{6}{7}+\frac{2}{14}+\frac{5}{14}=\frac{12}{14}+\frac{7}{14}=\frac{19}{14}\)
Thuc hien phep tinh bang cach tinh nhanh :
a) 4/9 + 3/2 + 6/36.
b) 2/7 x 5/17 + 12/7 x 15/17.
c) 2,34 + 5,18 + 7,66.
d) 7/11 : 3/4 + 7/11 : 1/4.
GIUP MINH MINH DANG CAN GAP.
Thuc hien phep tinh :
a) 4 phan 5 + -7 phan 15 . 1, 25
b) 2 phan 5 + 3 phan 5 . ( 4 1phan2 - 3,25)
\(\frac{4}{5}+\frac{-7}{15}.1,25\)
\(=\frac{4}{5}+\frac{-7}{12}\)
\(=\frac{13}{60}\)
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a) \(\frac{4}{5}\)+\(\frac{-7}{15}\) x \(1,25\)
= \(\frac{4}{5}\)+ \(\frac{-7}{15}\)x \(\frac{5}{4}\)
= \(\frac{4}{5}\)+\(\frac{-7}{12}\)
= \(\frac{48}{60}\)+ \(\frac{-35}{60}\)
= \(\frac{13}{60}\)
b \(\frac{2}{5}\)+ \(\frac{3}{5}\)x \(\left(4\frac{1}{2}-3,25\right)\)
= \(\frac{2}{5}\)+\(\frac{3}{5}\)x \(\left(\frac{9}{2}-\frac{13}{4}\right)\)
=\(\frac{2}{5}\)+\(\frac{3}{5}\)x\(\frac{5}{4}\)
=\(\frac{2}{5}\)+\(\frac{3}{4}\)
= \(\frac{8}{20}\)+\(\frac{15}{20}\)
=\(\frac{23}{20}\)