bai 1 tinh a biet : 267 +a 327= 488 * 2
b) tinh tong a+b, biet a,b la cac so tu nhien va 999<a<b<1002
bai 2 tong cua hai so tu nhien se thay doi nhu the nao neu ta tang tung so hang len gap 9 lan.
b tong cac chu so coua mot so co hai chu so la 12. neu doi cho cac chu so thi so moi hon so ban 18 don vi. tim so do?
c ba so co tong la 1458. so thu nhat bang 1/3 so thu hai. so thu hai bang 3/2 so thu ba. tim 3 so do.
bai 3 tim 2 so , biet so lon co 3 chu so va gap 9 lan so be va neu xoa chu so 4 o hang tram cua so lon thi duoc so be
b) cho phan so 7/8. hay tim 1 so sao cho khi tu so tru di so do va mau so cong voi so do ta duoc 1 phan so moi bang 1/4.
c) hieu cua hai so bang 315. tim 2 so do, biet rang neu xoa di chu so 0 o hang don vi cua so lon thi duoc so be.
Loga
Sinh Học lớp 12
