Consider the steps for solving 3x^2 - 42x 9 = -5 step 1: 3x^2 - 42x = -14 step 2: 3(x^2-14x) = -14 step 3: 3(x^2- 14x 49) = -14 number should be added to the right side of the equation?

In simplfying equations, it is important to follow PEMDAS rules. We do as follows:

3x^2 - 42x 9 = -5

step 1: 3x^2 - 42x = -14
 
step 2: 3(x^2-14x) = -14

step 3: 3(x^2- 14x + 49) = -14 + 49(3) = -14 + 147

Therefore, the number that should be added to the equation is 147.

Hope this helped. Have a nice day.