The highest common factor (HCF) is found by identifying all common factors of two numbers and selecting the largest one. For example, 8 and 12 have common factors of 1, 2 and 4. The highest common ...

Now, there is clearly a common factor of 3 between the numerator and denominator. Cancelling this through the fraction gives t + 2 t. There are no more common factors in this expression.