Ta có: \(\frac{a+6}{b+21}=\frac{a}{b}\Rightarrow\frac{a}{b}=\frac{6}{21}=\frac{2}{7}\)
\(\Rightarrow\frac{a}{b}=\frac{2}{7}\)
ban oi co bao nhieu p/s nhu vay co ma
CHO PHAN SO 13/18 .neu them 25 vao tu thi phai them vao mau bao nhieu de gia tri phan so ko doi
cho phan so 61/111 tim so tu nhien n biet rang neu cung them n vao tu so va mau so thi duoc phan so co gia tri 7/12
giap giup minh cam on nhieu\
Tim phan so \(\frac{a}{b}\)biet rang neu them 6 vao tuva them 21 vao mau thi gia tri a/b khong doi
chi tiet giupminh nha
GIA TRI 1 PHAN SO THAY DOI THE NAO NEU TA THEM VAO TS VA GIU NGUYEN MS
GIA TRI 1 PHAN SO THAY DOI NHU THE NAO NEU TA THEM VAO TS 1 SO BANG MS VA GIU NGUYEN MS
1a, cho tap hop A={x la so tu nhien/x=7k+3; k la so tu nhien ;x < hoac = 150}
- hay liet ke cac phan tu cua A tu nho den lon
-tinh tong cac phan tu cua A
b, tim thuong cua mot phep chia biet rang neu them 15 vao so bi chia va them 5 vao so chia thi thuong va so du khong thay doi
c, tim 1so co 2 chu so sao cho
[(a.10+b):b=3b
tim phan so toi gian a/b sao cho neu the 6 vao tu so va 21 va ms thi gia tri phan so khong thay doi , ai nhanh nhat minh ket ban luon ( co loi giai)
Tim phan so toi gian a/b biet :
a) Cong tu voi 4, cong mau voi 10 thi gia tri phan so ko doi
b) Cong mau vao tu, cong mau vao mau cua phan so thi duoc phan so moi bang 2 lan phan so da cho.
Neu them vao so bi chia 1/2 gia tri cua no va bot so chia di 0,5 gia tri cua no thi thuong moi so voi thuong cua phep chia ban dau thay doi bao nhieu lan:
Tim phan so co mau bang 9, biet rang khi cong tu voi 10 va nhan mau voi 3 thi gia tri cua phan so khong thay doi
