Let P = potential people in the pool.
430 are already there so we have to include that first.
430 + p
The sign says the maximum capacity is 600. Meaning it cannot go over 600 people. So, our equation must a less than or equal to sign.
430 + p ≤ 600
Now subtract the 430 from both sides to isolate variable P.
p ≤ 600 - 430
p ≤ 170
No more than 170 more people can enter the pool if 430 are already in the pool... that is a huge pool...