#### Answer

x = 40

#### Work Step by Step

1. Given: 0.05x + 0.10(200 - x) = 0.45x
2. Distribute: 0.05x + 20 - 0.1x = 0.45x
3. Multiply both sides by 10 to the 2nd power to turn decimals into whole numbers:
100(0.05x + 20 - 0.1x) = (0.45x)100
5x + 2000 - 10x = 45x
4. Add and subtract: -50x = -2000
5. Divide: x = 40
6. Check: 0.05*40+ 0.10(200 - 40) = 0.45*40
18 = 18, so 40 is a correct solution of the equation.