A rational number -real number that can be expressed exactly as a fraction whose numerator is an integer and whose denominator is a non-zero integer.
Between two two different types of groups, the highest common factor need to be found out.
\\(420 = 130\\times 3+ 30\\)
\\(130 = 30\\times 4+ 10\\)
\\(30 =10\\times 3+0\\)
The HCF is 10.
n(n-1) = n2- n = (2q)2- 2q =4q2 - 2q =2q(2q-1) [n is even]
n(n-1) = (2q+1)2 - (2q+1) = 4q2 +2q =2q(2q+1) [n is odd]
The HCF need to be found.
\\(132 = 57\\times 2+18 \\)
\\(57 = 18\\times 3+3\\)
\\(18 =3\\times 6+0\\)
The HCF is 3.
Use the division of a number by prime numbers method
hcf is the highest comman factor
