cho ps a\b rut gon 3\5 neu them 6 vao mau giu nguyen tu ta duoc 1 ps moi rut gon =2\3 tim ps a\b
Cho phan so A/B co B-A = 21 . Phan so A/B sau khi rut gon thi duoc phan so la 16/23 .Tim A/B.
cho PS \(\frac{a}{b}\) có b - a = 21/.PS \(\frac{a}{b}\) sau khi rút gọn thì được PS \(\frac{16}{13}\).tim PS \(\frac{a}{b}\)
cho 2 phan so 5/8va 4/5 .tim ps a/b sao cho dem ps 5/8cong ps a/b va dem ps 4/5 tru a/b thi duoc 2 ps ma ps naygap 2 lan ps kia
cho 2 phan so 6/7 va 2/9 tim P/S a/b sao cho khi them a/b vao moi PS ta duoc 2 PS co ti so la 3
cho phan so a/b . Neu rut gon phan so a/b thi ta duoc phan so 3/4 . Neu cong them 15 don vi vao tu so roi rut gon thi duoc phan so 7/6. Tim phan so a/b
cho ps 4/5 va 4/6. hay tim 7 phan so vua be hon 4/5 vua lon hon 4/6 rut gon cac ps do
cho phan so 23/35 tim mot so tu nhien biet rang neu cung them so tu nhien do vao ca tu so va mau so da cho ta duoc phan so moi va sau khi rut gon phan so moi nay ta duoc 5/7.
tim 1 ps = 3/4.biet neulay ts+5 ta duoc ps moi=4/5