I need the correct answer this my last assignment for Algebra 2

Nnnnneeedd 1.find the residual if you know the actual number is 5.2 and the predicted value is 4.8

Which is the most efficient first step to solve x in the equation 3.7x - 18 = -4.3x -34 a. add 3.7x to both sides of the equation. b. add 4.3x to both sides of the equation. c. subtract 18 from both sides of the equation. d. subtract 34 from both sides of the equation.

Geometry answer picture question pls . reason and statements