to solve for x try moving everything else to the otherside
in x - 9.2 = 13.8
there is a - 9.2 so to move it to the other side you add 9.2 to both sides of the equation
x -9.2 +9.2 =13.8 +9.2
the 9.2 cancel each other out which leaves
x = 13.8 +9.2
then you just add 13.8 +9.2 to find what x equals