Step 1: Line up the equations so that the variables are lined up vertically.
Step 2: Choose the easiest variable to eliminate and multiply both equations by different numbers so that the coefficients of that variable are the same.
Step 3: Subtract the two equations.
Step 4: Solve the one variable system.
Step 5: Put that value back into either equation to find the other equation.
Step 6: Reread the question and plug your answers back in to check.
The Formula is 4 x Pi x Radius Squared . surface area of sphere = 4 x pi x radius x radius where "x" indicates multiplication and pi = approximately 3.141592654 4 * pi * r^2