E=1-2-3+4+5-6-7+8+...+21-22-23+24
a,2/9-5/7+20/33+8/21+5/18-6/22
b, 1/2+1/3-1/4+1/6+1/8+1/16+1/32+1/64+1/128
c,5-1/2-5/6-11/12-19/20-29/30
các bn giúp mk nha
Tìm x biết : a) 2x+3/15 = 7/5. b) x-2/9 = 8/3. c) -8/x = -x/18 d) 2x+3/6 = x-2/5. e) x+1/22 = 6/x f) 2x-1/2 = 5/x g) 2x-1/21 = 3/2x+1 h) 10x+5/6 = 5/x+1
Tính:
a) -5/7(14/5 - 7/10) : |-2/3| - 3/4(8/9 + 16/3) + 10/3(1/3 + 1/5)
b) 17/-26(1/6 - 5/3) : 17/13 - 20/3(2/5 - 1/4) + 2/3(6/5 - 9/2)
c) -8/9(9/8 - 3/2) + 5/4 : (5/2 - 15/4) - 3/4(10/9 - 8/3) : (-1/3)
d) 21/10 : (12/5 - 9/10) . (-4/7) - 3/2(1/6 - 7/12) + 1/5(3/2 - 1/4)
Tính hợp lí:
a.[(3/4+11/13-15/27)/(3/2+22/13-10/9)]+(1/1*2)+(1/2*3)+(1/3*4)
b.(7*12^8*5^4-6^9*20^4)/(6^10*10^5-7*3^9*80^4)
a,5^x+4-3×5^x+3=2×5^11
b,3×5^x+2+4×5^x-3=19×5^10
c,6×8^x-1+8^x-1=6×8^19+8^21
d,5×2^x+3×2^x+2=5×2^5+3×2^7
{(-5/7)-7/9+9/11-11/13}x(3-3/4)
(10/21+14/27-6/11+22/39):(2-2/3)
RÚT GỌN ( LỚP 7 ) :
1. 210 . (-6)15/ 88 . (-27)5
2. 105 - 105 . 3/ 105 . 11
3. 415 . 1259/ 2013 . 516
4. 152011 . (-7)2012/ 352012 . 32011
5. 735 . 2722/ 334 . 2133
6. 733 . 2722/ 330 . 2135
7. 25 . 153/ 63 . 102
8. 810 + 420/ 425 + 645
9. (-7)4 . 36/ 92 .73
10. 912 . 258/ 4510 . 56
Ai làm đúng có lời giải rõ ràng mình kick cho nhaa toán lớp 7
( -5/7 - 7/5 + 9/11 - 11/13 ) * ( 3-3/4) : ( 10/21 + 14/27 - 6/33 + 22/39) : ( 2-2/3)
1. Thực hiện phép tính
G=(-5/7-7/9+9/11-11/13).(3-3/4)
phần (10/21+14/27-6/11+22/39):(2-2/3)
