Answer:
y=5x+9/20
Step-by-step explanation:
If only + numbers are acceptable, then the numbers divisible by 810 are represented by {810n}, where n = {0, 1, 2, 3, ... }
The answer is fairly simple. Each week they sing 8 songs, and so in 5 weeks they would sing 8x5 songs (which is 40) in 6 weeks, they would sing 8x6 songs (which is 48) and in 7 weeks 7x8 songs (which is 56)
