Tính:
a,\(D=\frac{2.8^9.27+4.6^9}{2^7.6^7+2^7.40.9^4}\)
b,\(E=\frac{\left(\frac{2}{3}\right)^3.\left(\frac{-3}{4}\right)^2.\left(-1\right)^5}{\left(\frac{2}{5}\right)^2.\left(\frac{-5}{12}\right)^3}\)
1. Tính hợp lí:
a) B = 1/2 - [ 3/8 + ( -7/4 ) ]
b) -4/12 - ( -13/39 - 0,25 ) + 0,75
c) 1/2 - 1/3 + 1/23 + 1/6
d) ( -13/7 - 4/9) - ( -10/7 - 4/9 )
e) ( 7/8 - 5/2 + 4/7 ) - ( -3/7 + 1 - 13/8 )
f) -3/7 + ( 3 - 3/4 ) - ( 2,25 - 10/7)
g) ( 5/3 - 3/7 + 9 ) - ( 2 + 5/7 - 2/3 ) + ( 8/7 - 4/3 - 10 )
a,3/2-5/6:(1/2)2+\(\sqrt{0,25-\sqrt{\dfrac{1}{4}}}\)
b,-4/3:2/9+13/12:-13/8
c,(-1/2)2-[-1/6:|-1+5|-\(\sqrt{64}.\left(\dfrac{1}{4}\right)^2\)
d,15^11.5^7.9^2/5^18.27^6
Bài 1: thực hiện phép tính
a, (3/8 + -3/4 + 7/12) : 5/6 + 1/2
b, -7/3. 5/9+ 4/9. (-3/7)+ 17/7
c,117/13 - (2/5 + 57/13)
d, 2/3 - 0,25 : 3/4 + 5/8 .4
Bài 2: tìm x biết
a, 2/3 x - 1/2 = 1/10
b, -2/3 -1/3 (2x -5) = 3/2
c, (3x -1) (-1/2 x + 7) =0
d, 17/2 - | 2x - 3/4 | =-7/4
e, (x + 1/25) +17/25 = 26/25
a, Tính tổng: 5/6+5/12+5/20+.......+5/132
b, Tìm x: 1/2.4+1/4.6+......+1/x(x+2)
c,Tính tổng: -1/2 . -2/3 . -3/4..........-99/100
3/4.8/9.15/16.............9999/10000
Rút gọn các biểu thức sau :
A=\(\frac{2.8^4.27^2+4.6^9}{2^7.6^7+2^7.40.9^4}\)
B=\(\frac{\left(\frac{2}{3}\right)^3.\left(-\frac{3}{4}\right)^2.\left(-1\right)^5}{\left(\frac{2}{5}\right)^2.\left(-\frac{5}{12}\right)^3}\)
1.Rut gọn
a)2^15.9^4/6^3.8^3
b)2^7.9^3/6^5/6^5.8^2
Tìm x
a, -2/3 . x + 4 = 12
b, -3/4 + 1/4 : x = -3
c, ( 2x - 1/3 ) ( 0.5x +0,25 ) = 0
bỏ ngoặc rồi tính
1|(-2/5)+1/3]-(3/5-1/3)
2(3/2-3/4)-(0,25+1/2)
sos