The formula for the amount with simple interest is a = p(1 + rt). find t if a = 168, p = 150, and r = 0.08.

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