1. x^3 + 10 x 23 = 355
10 x 23 = 230
355 - 230 = 125
cube root of 125 is 5
So,
x = 5
2.
Bob = 5 per day for 100 years
Billy = 10 per day for 100 years minus 3 every month
Bob = 5 x 365 = 1,825 per year
Billy = 5 x 2 x 365 = 10 x 365 = 3,650 per year without reduction of 3 apples per month
12 months per year x 3 apples = 36 so 3,650 - 36 = 3,614 apples per year so billy = 3,614 apples per year
Bob = 1,825 x 100 = 182,500 apples after 10 decades
Billy = 3,614 x 100 = 361,400 apples after 10 decades
So,
Bob = 182,500 apples
Billy = 361,400 apples
Not including leap years
Including leap year would =
Bob = about 182,625 apples
Billy = about 367,650 apples
Because leap year is every 4 years and 100 years / 4 years = 25 years so
Bob = 1,830 x 25 + 1,825 x 75 = 182,625 apples
Billy = 3,624 x 25 + 3,614 x 75 = 367,650 apples
Sorry if it looks complicated
Hope this helps ;)