-2(t-7)-(t+8)=8

- 2 ( t - 7 ) - ( t + 8 ) = 8

- 2 * t - 2 * ( - 7 ) - t - 8 = 8

- 2 t + 14 - t - 8 = 8

- 3 t + 6 = 8 Subtrac 6 to both sides

- 3 t + 6 - 6 = 8 - 6

- 3 t = 2 divide both sides by - 3

t = - 2 / 3