12 = - 3t + 9
subtract 9 from each side
12 - 9 = -3t + 9 - 9
3 = - 3t
divide both sides integers by - 3
3/- 3 = (- 3/ - 3)t
- 1 = t
=======check in original equation
12 = - 3(- 1) + 9
12 = 3 + 9
12 = 12
=======checks
8
t = -11/10
2t - 12 - 3t = 60 -1t - 12 = 60 -1t -12 +12 = 60 + 12 -1t = 72 t = -72
15t+25 = 5(3t+5)
Yes and t = 1 in both equations
3t + 7 = 2t - 5 3t = 2t - 12 t = -12
3t+11 = 29 3t = 29-11 3t = 18 t = 6
s = 7, t = -3
4+3t = 22 3t = 22-4 t = (22-4)/3 t = 6
-12t+4
S = 3 st + 3t = 6 st = 6 - 3t s = (6 - 3t)/t = 6/t - 3
8
In 2t+8 19
t = -11/10
2t - 12 - 3t = 60 -1t - 12 = 60 -1t -12 +12 = 60 + 12 -1t = 72 t = -72
15t+25 = 5(3t+5)
Yes and t = 1 in both equations