bai 1, thuc hien phep tru
a, (a-1)-(a-3)
b, (2+b)-(b+1)
c, -(1-2)+(5-c)
d, -(a-c)-(a-b+c)
bai 2, tim x, biet
a, -x+8= -17
b, 35-x=37
c, -19-x= -20
d, 2130-(x+130)+72= -64
giup minh voi, minh can gap, cam on cac ban nhieu
a) CHO TONG A = 270 + 3150 + 150 . KHONG THUC HIEN PHEP TINH XET XEM TONG TREN CO CHIA HET CHO 2 ; 3 ; 5 ;9
b) CHO B = 12+ 18 + 21 + x VOI x THUOC N . TIM DIEU KIEN CUA x DE A CHIA HET CHO 3 , DE A KHONG CHIA CHO 3
GIUP MINH VOI CA NHA OI . AI TRA LOI DUNG SE CO 3 LIKE
Bai 1:thuc hien phep tinh
A,48×19+48×115+134×52
B,56:54+23×22-12017
giup minh voi!!!!!
BAI1: CHO BIEU THUC.
A= 1494 x 1495 x 1496
KHONG THUC HIEN PHEP TINH GIAI THICH VI SAO
a; a chia het 180
b; a chia het 495
BAI2:CHUNG MINH RANG : n thuoc N thi cac so sau chia het cho 9
a; 10n-1
b; 10n+8
BAI3: TIM DIEU KIEN n thuoc N de so 10n-1 chia het cho 9 va 11
thuc hien phep tru
(2+3b)-(2b-2)+5
-(-3c+1)+5c-7-8c
A=a^2+2a^2-1/a^2+2a+2a^2+1
a, rut gon bieu thuc
b, chung to rang voi a thuoc Z thi A khong toi gian
Voi gia tri nao cua x thuoc Z ; phan so sau co gia tri la 1 so nguyen
a. A=3/x-1
b. C=2x+1/x-3
c. D=x mũ 2 tru 1/x+!
1,thuc hien phep tinh hop li
a,187+[923-(923+887)]
B, 39.187+30^2-78.39
giup minh giai nhung thuc hien phe tinh nha
thuc hien phep tinh a)6^2:4 x 3+2x5^2 b)5x4^2 -18:3^2
