Answer:
7-8t
Step-by-step explanation:
3(1-t)-5(1-t)+9= 3-3t-5-5t+9
2t-7
3 x 1= 3 - 3t
-5 x 1= -5 + 5t
-3t + 5t = 2t
3 - 5 = -2 + 9 = -7
3 - 3t - 5 + 5t + 9 = 2t - 7
