Mechanics M1 problem-help needed with constant acceleration

Hi,

The question asks, 

A body moving in a straight line with constant acceleration takes 3 sec and further 5 sec to cover two successive distances of 1m. Find acceleration.(Hint: use distances of 1m and 2m from the start of motion) 

I am unable to figure out how to solve this. Could you please show the calculations to get the same answer presented in the book, which is -1/30 m/s^2 ? 

Thanks.

Student X

Let us employ the formula s=ut+1/2 *at^2 

When the first metre is covered, substituting s=1 and t=3 gives 

3u+ 9a/2 = 1 -----------------(1) 

When the first two metres are covered, substituting s=2 and t= 3+5=8 gives 

8u+ 32a = 2 ====> 4u+16a =1 -------(2)

Solve these two equations simultaneously, you should be able to retrieve the answer for the acceleration shortly.

Peace.

Best Regards,

Mr Koh