Find the highest common factor of $$126, $$378, and $$189.

Sure, here are the steps to find the highest common factor (HCF) of 126, 378, and 189:

Step 1: Prime factorization of the numbers

• Prime factorization of 126 = 2 * 3^2 * 7
• Prime factorization of 378 = 2 * 3^3 * 7
• Prime factorization of 189 = 3^3 * 7

Step 2: Identify the common factors The common factors are 3^2 and 7.

Step 3: Multiply the common factors Multiply the common factors to get the HCF. So, 3^2 * 7 = 9 * 7 = 63.

Therefore, the highest common factor of 126, 378, and 189 is 63.