Algebraic Techniques, SM-Bank 145 State the highest common factor of \(15xy\ \text{and}\ 20y\). (1 mark) Show Answers Only \(5y\) Show Worked Solution \(\text{HCF of}\ 15\ \text{and}\ 20=5\) \(\text{HCF of}\ xy\ \text{and}\ y=y\) \(\therefore\ \text{HCF of}\ 15xy\ \text{and}\ 20y=5y\)