Why can you write a subtraction problem as an addition problem? how do you write a subtraction problem as an addition problem?

Someone answer asap for ! michele pushes a box d meters across a floor. she uses a force f, in newtons, to push the box. she pushes the box for t seconds. the formula p = fd/t calculates the power, p, in watts, that it takes for michele to complete the task. solve the formula for d.

If f(x)=x+7 and g(x)=1/x what is (fog)(x)

The sum of the squares of two numbers is 8 . the product of the two numbers is 4. find the numbers.