I believe what you need to do is multiply 3 by each number.
To start, 3*584 is 1752. Expanded form written out would be (3*500)+(3*80)+(3*4). Simply multiply all the numbers and then add them together. 3*500=1,500; 3*80=240; 3*4=12. 1,500+240=1740+12=1752. Hope this helps! :)