Write an equation to describe this : pick a number (x) halve it add 10 and the result is 17

In physics, if a moving object has a starting position at so, an initial velocity of vo, and a constant acceleration a, the the position s at any time t> o is given by: s = 1/2 at ^2 + vot+so solve for the acceleration, a, in terms of the other variables. for this assessment item, you can use^to show exponent and type your answer in the answer box, or you may choose to write your answer on paper and upload it.