Question

Fill in the missing reason. 
3.
plz help

Answer 1

The answer is subtracteion property

Answer 2

We have 5x+9 = 309 in second step.

Then we need to get rid of 9. ANd for that we need to do subtraction to both sides, that is

5x +9-9=309-9

5x =300

THerefore the reason for this step is Subtraction property .