1) Multiply the number of your brothers, "x" by 2.
2x
2) Add 3.
2x+3
3) Multiply by 5.
(2x+3)(5)
4) Add the number of your sisters, "y".
(2x+3)(5)+y
5) Multiply by 10.
[(2x+3)(5)+y](10)
6) Add the number of your living grandparents, "z".
[(2x+3)(5)+y](10)+z
7) Subtract 150.
[(2x+3)(5)+y](10)+z-150
NOW SIMPLIFY STEP 7
Work inside the brackets first, we need to multiply by 5.
[10x+15+y](10)+z-150
Now multiply by 10.
100x+150+10y+z-150
Subtract 150 from the 150.
100x+10y+z
  The number of brothers, "x", is in the 100's place, the number of sisters, "y", is in the 10's place, and the number living grandparents, "z" is in the 1's place.