a ,/ 2x - 4 / + ( 3y - 3 ) mu 2 = 0
b , / 3x - 1 / + ( y - 2 ) mu 2 > hoac = 0
giup minh voi chieu mai mk phai di hoc roi
Tim x biet:
A. (x-3/4).(3x+1/2)lon hon hoac bang 0
B. (2x+1).(4x+3)be hon hoac bang 0
viet tong sau thanh binh phuong cua mot so tu nhien , n lon hon hoac bang 1
1 mu 8 + 2 mu 8 + 3 mu 8 ......... n mu 8
cho A= 1+2 mũ 1+ 2 mũ 2+ 2 mũ 3+......+ 2 mũ 2007
a) Tính 2A
b) Chứng minh: A= 2 mũ 2008 -1
tim x nguyen biet:
a 8.(x mu 2 +3).(5-x)
b)(2x + 1)mu 2=25
c) (1-3x)mu3 =64
d)(4-x)mu3 =-27
e) xmu2 -5x =0
5 mu n nhan 5 mu n cong 1 nhan 5 mu n cong 2 be hon hoac bang 10 mu 18
a, 2nhan16>hoac bang 2 mu x nhan 74
b, 25 nho hon 5mu x nhan 5 mu 2 nho hon hoac bang 125
1. cho 4 stn a lon hon hoac bang b, b lon hon hoac bang c, clon hon hoac bang d.
CM:(a-b)(a-c)(a-d)(b-c)(b-d)(c-d)
2. CM: co the tim dc 1 stn k sao cho: (1997^k)-1 chia het cho 10^4
3. tong cac chu so cua 1 so chinh phuong co the bang 1995 dc k?
4. tong cua 1995 stn khac 0 dung bang 1995. Hoi UCLN cua chung la bao nhieu?
Tìm x;y biết -(x+3) mu 2 trụ so đoi của y+7 > hoac =0