Part A:
The HCF is an acronym for Highest Common Factor. An unknown number and 63 have an HCF equal to 9. The factors of 63 are 9 and 7. There are lots of numbers to which the HCF with 63 is 9. These should be divisible by 9 but not by 7. That being said, the answers could be 9, 18, 27, etc.
Part B:
LCM is the acronym for least common multiple. Given that the LCM of a number and 48 is 144, the other number could be determined by dividing 144 by 48. If we let x be the number,
x = 144/48
x = 3
The goal in solving an equation is to get the variable by itself on one side of the equation and a number on the other side of the equation. To isolate the variable, we must reverse the operations acting on the variable.
Answer:
C
the answer is c I have done this before