Answer:
proportional graph is a straight line that always goes through the origin. A non-proportional graph is a straight line that does not go through the origin.
Step-by-step explanation:
Answer:
Speed of river's current = 5 mph
Step-by-step explanation:
Let 'd' be the distance covered
Let x be the speed of the rivers current
Speed upstream = 15-x
speed downstream = 15+x
Time = distance / speed
time upstream = 
time downstream = 
the ferry trip upstream takes twice as long as its return trip downstream
= 
divide both sides by d
= 
cross multiply


Add 2x on both sideds

subtract 15 from both sides and divide by 3

x=5
Speed of river's current = 5 mph
Answer:
71424
Step-by-step explanation:
Answer:
80 + 18i
Step-by-step explanation:
i² = -1
x = i + 9
x² = (i + 9)²
Applying; (a + b)² = a² + 2ab + b² concept,
x² = i² + 18i + 81
We know that i² = -1
So x² = -1 + 18i + 81
x² = 81 - 1 + 18i = 80 + 18i