\(b,=-\dfrac{3}{5}-\dfrac{2}{5}+2=-\dfrac{5}{5}+2=-1+2=1\\ c,=-\dfrac{5}{11}-\dfrac{6}{11}+1=-\dfrac{11}{11}+1=-1+1=0\)
\(b,=-\dfrac{3}{5}-\dfrac{2}{5}+2=-\dfrac{5}{5}+2=-1+2=1\\ c,=-\dfrac{5}{11}-\dfrac{6}{11}+1=-\dfrac{11}{11}+1=-1+1=0\)
bài 2 . thực hiện phép tính
a. -1,75-(-1/9-2 1/18)
b. -1/12- (2 5/8-1/3)
c. -5/6-(-3/8+1/10)
Bài 3 :tìm x ,biết :
a. 11/13-(5/42-x)=(-15/28-11/13)
b. x+1/3=2/5-(-1/3)
c. 3/7-x=1/4-(-3/5)
Tính
a) 2/3 -4 . (1/2 +3/4)
b) (-1/3 + 5/6) .11 7
c) -5/11 . 7/15 . 11/-5 . (-30)
d) -1/6 . -15/19 . 38/45
e) -5/9 . 3/11 + ( -13/18 . 3/11)
f) ( 2 2/15 . 9/17 . 3/32) : -3/17
1)
a) 2/3 - 4 .(1/2 +3/4)
b) (-1/3 + 5/6) . 11-7
c) 3/4 - 3/5 + 3/7 + 3/11 / 13/5 - 13/5 + 13/7 + 13/11
d) 3/11 . 4/15 + 19/15 . -3/11
các bạn giúp mình nhé !
8)Tính nhanh :
a) -3/7+5/13+ -4/7
b)-5/8+3/4+ -1/5+-3/8+1/4
c)6/7.8/13+6/7.9/13+ -3/13.6/7
d)-5/7.2/11+ -5/7.9/11+1 5/7
e)11 3/13 - (2 4/7+5 3/13)
f) (1-1/2)(1-1/3)(1-1/4)(1-1/5)
Tính giá trị biểu thức :
A = ( 3 - 1 / 4 + 2 /3 ) - ( 5 1/3 - 6/5 ) - ( 6 - 7/4 + 3 /2 )
B = 1 / 3 - 3 / 4 - ( -3/ 5 ) + 1 /64 - 2 / 9 - 1 /36 + 1 / 15
C = 1 / 3 - 3 / 5 + 5/7 - 7/ 9 + 9 /11 - 11 / 13 + 13 / 15 + 11/ 13 - 9 /11 + 7 / 9
D = 1/99 - 1 /99 x 98 - 1 / 98 x 97 - 1 /97 x 96 - ........ - 1 / 3x 2 - 1/ 2 x 1
Tính giá trị biểu thức :
A = ( 3 - 1 / 4 + 2 /3 ) - ( 5 1/3 - 6/5 ) - ( 6 - 7/4 + 3 /2 )
B = 1 / 3 - 3 / 4 - ( -3/ 5 ) + 1 /64 - 2 / 9 - 1 /36 + 1 / 15
C = 1 / 3 - 3 / 5 + 5/7 - 7/ 9 + 9 /11 - 11 / 13 + 13 / 15 + 11/ 13 - 9 /11 + 7 / 9
D = 1/99 - 1 /99 x 98 - 1 / 98 x 97 - 1 /97 x 96 - ........ - 1 / 3x 2 - 1/ 2 x 1
\(b) 5^{x+4} - 3 . 5^{x+3} = 2. 5^{11} \)
\(c) 2 . 3^{x+2} + 4 . 3^{x+1} = 10 . 3 ^{6}\)
\(d) 6 . 8 ^ {x-1} + 8 ^ {x+1} = 6 . 8^ {19} + 8 ^ {21}\)
Tính:
a) \(\sqrt{\dfrac{9}{16}}-\dfrac{5}{6}+\dfrac{3}{2}\) b) \(\left(\dfrac{1}{9}+\dfrac{2}{3}\right)^2-\dfrac{5}{3}:\sqrt{25}\)
c)\(\dfrac{5}{11}.\left(-\dfrac{3}{7}\right)+\dfrac{5}{11}.\left(\dfrac{-5}{7}\right)+\left(-\dfrac{8}{7}\right).\dfrac{6}{11}\)
d) \(\dfrac{2^8.2^{18}}{8^5.4^6}\)
Tính nhanh:
\(a,A=\dfrac{\dfrac{5}{4}+\dfrac{5}{5}+\dfrac{5}{7}-\dfrac{5}{11}}{\dfrac{10}{4}+\dfrac{10}{5}+\dfrac{10}{7}-\dfrac{10}{11}}\)\(b,B=\dfrac{2+\dfrac{6}{5}-\dfrac{6}{7}-\dfrac{6}{11}}{\dfrac{2}{3}+\dfrac{2}{5}-\dfrac{2}{7}-\dfrac{2}{11}}\)
giúp mình với
tìm x biết
1) x=-1/2 + 3/4 2) x - 1/5 = 2/11 3) x - 5/6 = 16/42 + -8/56
4) x/5 = 5/6 + -19/30 5) |x| - 1/4 = 6/18 6)x = -1/2 +3/4
7) x/15 = 3/5 + -2/3 8)11/8 + 13/6 = 85/x 9) x - 7/8 = 13/12
10) x - -6/15 = 4/27 11) -\(\dfrac{-6}{12}\)+ x = 9/48 12) x - 4/6 = 5/25 + -7/15