18= 1/2[g(t- 1)？ ] (2)

( 1)/(2) De: 16/9=t？ /(t- 1)？

9t？ = 16(t- 1)？

7t？ -32t+ 16=0

Solve the equation: x=4/7 or t=4.

Carry once (1)

Get g= 196 or g=4.

So there are two solutions to this problem: t=4/7 g= 196.

t=4 g=4