Sine he runs 2 miles on Monday, we already have a +2.
Then, he runs by a constant rate of 1, which is the constant rate of change per day.
Let x represent the number of days he runs and y the total amount of miles he runs. Now, the equation is y = x + 2
However, he needs to run at least 6 miles. At least means greater than or equal to. The values for y can be greater than 6, or equal to 6.
y ≥ 6
y = x + 2
Now substitute x + 2 for y.
x + 2 ≥ 6
Subtract 2.
x ≥ 4
This is the inequality. He has to run for at least 4 days.