I think you divide 5/9 divided by 2/3.
5/9 divided by 2/3=4/3 simplified=2/3.
Just know I'm terrible at math so this could be like totally off the hook crazy and wrong.
(4) is the y-intercept in the equation, and is where you plot it on the y-axis. (-3) is your slope. If you were to graph it, here is the link to how it looks like.
1 metric ton = 1,000 kilograms
To convert from kilograms to metric tons, divide by 1,000.
10,600÷1,000=10.6 metric tons
Find a common denominator between the two (this case it would be 18) and bring the fractions up, so 10/9 would be 20/18, and 3/2 would be 27/18. Then, multiply across, and simplify to lowest terms.
Riley's age = r
Riley's brother's age = r/4
If Riley was 11 five years ago, Riley is currently 11 + 5 years old, or 16 years old.
Now we just need to use r/4 to find Riley's brother's age:
16 /4 = 4
Riley's brother is 4 years old.
Hope this helps!