Hi,

I think you want to express this sum as one fraction and hence you are looking for the least common denominator which is the least common multiple (LCM) of 200, 400, 800 and 600. Find the prime factorization of each of the denominators.

200 = 2³ × 5²
400 = 2⁴ × 5²
600 = 2³ × 3 × 5²
800 = 2⁵ × 5²

From this you can see that if a number is a multiple of each of these its prime factorization must contain 5 twos, a three and two fives. Hence the least common multiple of 200, 400, 600 and 800 is

2⁵ × 3 × 5².

Can you complete the problem from here? Write back if you need more assistance.

Penny