To find the prime factor tree for 70, divide it by the smallest prime numbers until you get only prime numbers. The highest common factor (HCF) of 70 and 546 is 14.
To find the prime factor tree for 70, start by dividing 70 by the smallest prime number, which is 2. You get 35. Then, divide 35 by the smallest prime number, which is 5. You get 7. Since 7 is a prime number, the prime factor tree for 70 is:
2
/
70
\
5
\
7
To find the highest common factor (HCF) of 70 and 546, we look for the common prime factors of 70 and 546. From the prime factor tree of 70, we have 2 and 5 as prime factors. From the prime factor tree of 546, we have 2, 3, and 7 as prime factors. The highest common factor is the product of the common prime factors, which in this case is 2 x 7 = 14.