Solve 0.85x x 1.09 x 0.7 = 3250000/2.

Step-by-step solution

1. 1

   Reduce the right-hand side. $\dfrac{3{,}250{,}000}{2} = 1{,}625{,}000$, giving $0.85x \cdot 1.09 \cdot 0.7 = 1{,}625{,}000$.

2. 2

   Merge the three factors into one coefficient. $0.85 \cdot 1.09 = 0.9265, \qquad 0.9265 \cdot 0.7 = 0.64855.$ A $15\%$ cut, then a $9\%$ rise, then a $30\%$ cut leaves $64.855\%$ of the starting value - note this is not $15+9-30$ percent, because percentage changes compound multiplicatively.

3. 3

   Solve the resulting one-step equation. $0.64855x = 1{,}625{,}000 \quad\Longrightarrow\quad x = \frac{1{,}625{,}000}{0.64855}.$

4. 4

   Evaluate exactly, then round. Clearing the decimal, $x = \dfrac{32{,}500{,}000{,}000}{12{,}971} \approx 2{,}505{,}589.39$.

5. 5

   Verify the chain forward. $2{,}505{,}589.3917 \times 0.85 = 2{,}129{,}751.983$, $\times 1.09 = 2{,}321{,}429.661$, $\times 0.7 = 1{,}625{,}000.00$ - back to the target.

6. 6

   Compare with the 0.85 sibling. Replacing the last factor $0.85$ by $0.7$ shrinks the net multiplier from $0.787525$ to $0.64855$, so the required $x$ grows by the ratio $\tfrac{0.787525}{0.64855} \approx 1.2143$: from about $2.06$ million to about $2.51$ million.