This is just a simple question. First, substitute the equations by the given corresponding values.
168 = 150(1 + 0.08t)
Then simplify the equation by multiplying the 150 inside the parenthesis
168 = 150 + 12t
Then You must transpose the 150 to the left side and it will look like this,
168 - 150 = 12t
Then simplify it again.
18 = 12t
Then divide both sides by 12 to eliminate the 12 on the 12t.
18 = 12t
12 12
The answer would be 1.5 = t
