Z varies directly with x and inversely with y.
1 answer:
Answer:
z =
Step-by-step explanation:
Given that z varies directly with x and inversely with y then the equation relating them is
z = ← k is the constant of variation
To find k use the condition when x = 6 and y = 2, z = 15, thus
15 = ( multiply both sides by 2 )
30 = 6k ( divide both sides by 6 )
5 = k
z = ← equation of variation
When x = 4 and y = 9, then
z = =
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Answer:
Distance between automobile and the truck is 100 feet.
Step-by-step explanation:
Speed of the automobile towards the intersection = 30 ft per sec
Speed of the truck that crosses the intersection = 40 ft per sec.
Automobile is 120 feet apart when the truck passes through the intersection.
After 2 seconds distance traveled by the automobile = Speed × time
= 30 × 2
= 60 feet
So the distance of the automobile from the intersection = 120 - 60
= 60 feet
Distance traveled by truck in 2 seconds = 40 × 2
= 80 feet
Now distance between them can be calculated by Pythagoras theorem
Distance =
=
=
= 100 feet
Therefore, after 2 seconds distance between the truck and the automobile will be 100 feet.
