Answer: -6
Step-by-step explanation:
From the question, Elsa pumped 18 gallons of water out of her pool and this was done over a period of 3 minutes at a constant rate. Since it is done at a content rate, to get the change in the amount of water in the pool each minute, we divide 18 gallons by 3. This can be written mathematically as:
= 18 gallons ÷ 3
= 6 gallons
Change = -6
The change in the amount of water in the pool each minute will be -6gallons hope this helps
Answer:

Step-by-step explanation:
a) 
b) 
c) 
d) 
e) 
f) 
Answer:
n= 4f/5+90
Step-by-step explanation:
f= 5(n−90)
/4 (simplify)
f * 4=5(n−90) (multiply 4 on both sides)
4f=5(n−90) (regroup)
4f/5
=n−90 (divide 5 on both sides)
4f/5
+90=n (add 90 to both sides)
X + (x + 1) + (x + 2) = 126
3x = 123
x = 41
So the sides are 41, 42 and 43