Step-by-step explanation:
y = f(X) = 3x - 7
3x = y + 7
x= (y +7)/3
f ^-1(x) = (x + 7)/3
step 2 would be 10
step 4 would be 10x-x = 9x =7
x = 7/9
When you round; you round down if the number in the selected column is below 5 and you round up if the number is 5 and above.
Thus; if you apply this to your question:
784,072 then round up and you get 790,000
