Question

Tìm ước chung lớn nhất:

a) ƯCLN (420;700)

b) ƯCLN (13;20)

c) ƯCLN (16;24)

d) ƯCLN (60;90;135)

Answer 1

a. ƯCLN_{(420; 700)} = 140

b. ƯCLN_{(13; 20)} = 1

c. ƯCLN_{(16; 24)} = 8

d. ƯCLN_{(60; 90; 135)} = 15

Answer 2

\(a,420=2^2\cdot3\cdot5\cdot7;700=2^2\cdot5^2\cdot7\\ ƯCLN\left(420,700\right)=2^2\cdot5\cdot7=140\\ b,13=13;20=2^2\cdot5\\ ƯCLN\left(13,20\right)=1\\ c,16=2^4;24=2^3\cdot3\\ ƯCLN\left(16,24\right)=2^3=8\\ d,60=2^2\cdot3\cdot5;90=2\cdot3^2\cdot5;135=3^3\cdot5\\ ƯCLN\left(60,90,135\right)=3\cdot5=15\)