Answer:
Step-by-step explanation:
They all give 8r so that is not the distinguishing characteristic.
The first one in column A gives
12r + t - 4r + 6t
12r - 4r + t + 6t
8r + 7t
This is the third one in column B
2nd one in Column A
12r + 2t - (4r + 10t) Remove the brackets
12r + 2t - 4r - 10t Pay close attention to 10t becoming -10t. The minus sign effects both terms inside the brackets.
12t - 4t + 2t - 10t Combine
8r - 8t Now take out the common factor (8)
8(r - t) That's the top one in column B
3rd one in column A
12(r + t) - 6(r +t) + 4(r + t) - 2(r+t) They all have r+t so r + t is a common factor)
(r+t) [12 - 6 + 4 - 2] Combine
(r + t ) [ 8 ]
This is the second one in column B
The trick here is to look out for common factors. Don't remove the brackets. But it takes a bit of practice before you know that
