## Basic College Mathematics (10th Edition)

$3^{2}$ * 5
45 Try to divide 45 by the prime number 3 45 $\div$ 3 = 15 So 15 * 3 =45 Now again divide 15 by the prime number 3 15 $\div$ 3 = 5 45 = 3 *3 * 5 Because all the factors are prime. So the prime factorization of 45 is 3 *3 * 5 = $3^{2}$ * 5