Isolate the x. Treat the less than sign as equal sign. What you do to one side, you do to the other. Do the opposite of PEMDAS.
First, subtract 47 from both sides
4x + 47 (-47) < 7 (-47)
4x < -40
Next, divide 4 from both sides
(4x)/4 < (-40)/4
x < -40/4
x < -10
x < -10 is your answer
hope this helps