de bai: don gian bieu thuc
a/ x + 25 +(-17)+ 63
b/(-75) -(p+20)+95
giup minh voi , minh nick cho
Bai 1: Tinh nhanh:
a, -69+53+46+(-14)+78 b, 13-12+11+10-9+8-7-6+5-4+3+2-1
Bai 2: a,Tim gia tri nho nhat cua bieu thuc: A= |x+19|+|y-5|+1890
b, Tim gia tri lon nhat cua bieu thuc: B= -|x-7|-|y+13|+1945
Bai 3: Tim x,y thuoc Z biet: a, xy-3x= -19 b, 3x+4y-xy= 16
Bai 4: Tim x thuoc Z biet: a, x.(x+3)= 0 b, (x-2) (5-x)= 0 c, (x+1) (x2+1)= 0
d, -12 (x-5)+7 (3-x)= 5 e, 30 (x+2)-6 (x-5)-24x= 100 f, (x+1)+(x+3)+(x+5)+. . .+(x+99)= 0
Minh xin cam on truoc ! THANK YOU
tinh gia tri cua bieu thuc -90-(y+10)+100 voi p=-24
Cau1.Hay tinh hop li cac tong sau day
a) A=1/3+1/3^2+1/3^3+....+1/3^100
b)B=10/56+10/140+10/260+....+10/1400
Cau2
Cho C=2+2^2+2+3+...+2^99+2^100
a)Tinh tong C
b)Tim x de2^2x-1-2=C
c)Chung minh rang C chia het ch 31
Cau 3
a) So sanh: A=2005^2005+1/2005^2006+1 va B=2005^2004+1/2005^2005+1
b)Tim so nguyen m sao cho so m+6/m-1 la so nguyen
Cau4
Cho AB=x(cm) AC=7(cm) BC=2x-1(cm) .Timx sao cho ba diem A B C thang hang
Cau 5
a) Tim x,y thuoc N biet 2^x+624=5^y
b)Voi gia tri nao cua x ,y thi bieu thuc A=/x-y/+/x+1/+2013 dat gia tri nho nhat .Tim gia tri nho nhat do
Chu y dau ''/'' la dau gia tri tuyet doi
Cau 6
De chuan bi cho ki thi hoc sinh gioi, mot hoc sinh giai 35 bai toan.Biet rang cu moi bai dat loai gioi duoc thuong 20 diem moi bai dat loai kha trung binh duoc thuong 5 diem . Con moi bai yeu, kem bi tru 10. Lam xong 35 bai em do duoc thuong 130 diem .Hoi co bao nhieu bai loai gioi ,bao nhieu bai loaiyeu ,kem .Biet rang co8 bai kha va trung binh
Ai lam dung minh tich cho
Nho giai ra nha
tinh gia tri bieu thuc
A=5.(x-y) voi x=-4,y=2
B=a.(b+c)-b(a-c)
với a+b=-5 va c=10
don gian bieu thuc khi bo ngoac
-(a-b+c)-(a+b+c)
bai 1 : a, cho S=5+52+53+54+55+56+.........+52012 chung to S chia het cho 65
b, tim stn nho nhat sao cho khi chia cho 11 du 6, 4 du 1, 19 du 11
c, chung to A=10n+18n-1 chia het cho 27 ( voi n la so tu nhien )
bai 2
tim x,y biet 2x.(3y-2)+(3y-2)= -55
bai 3
cho bieu thuc a-b chia het cho 6
chung minh cac bieu thuc sau cung chia het cho 6
a, a+5b
b, a-13b
giup mik voi !!!!!!!!!!!!!
a, tim gia tri nho nhat cua bieu thuc :\(A=\)\(|x+19|+|y-5|+1890\)
b,tim gia tri lon nhat cua bieu thuc:\(B=-|x-7|-|y+13|+1945\)
Tim GTNN cua cac bieu thuc:
a,A=|x-1|+|x-2|+|x-3|+|x-4|+...+|x-10|
b,P=|3x-6|+|y2+1|+2015
Cach lam nua nhe
Lam nhanh minh se tick
