consider the steps for solving 3x^2 - 42x + 9 = -5 for x by completing the square.

step 1) 3x^2 - 42x = -14
step 2) 3(x^2 - 14x) = -14
step 3) 3(x^2 - 14x + 49) = -14 + ___

What number should be added to the right side of the equation?

Please help me !