Question:
The quantities x and y are proportional.
x y
5.8 7.5
11.2
Find the constant of proportionality (r) in the equation y=rx
Answer:
The constant of proportionality is 75/58 or 1.29
Step-by-step explanation:
Given
The table above
Required
Find the constant of proportionality
The question has an incomplete table but it can still be solved because x and y are proportional.
Given that
y = rx
Make r the subject of formula
Divide through by x
y/x = rx
y/x = r
r = y/x
When y = 7.5, x = 5.8
Substitute these values
r = y/x becomes
r = 7.5/5.8
Multiply denominator and numerator by 10
r = (7.5 * 10)/(5.8 * 10)
r = 75/58
In this case, it's best to leave the answer in fraction.
However, it can be solved further.
r = 75/58
r = 1.29 (Approximated)
Hence, the constant of proportionality is 75/58 or 1.29
Answer: 45
Step-by-step explanation:
Divide 90 by 2 and you will the the answer of 45.
Let the price of the tickets be 'x' and the number of tickets bought is 'y'
When the y inversely proportioned to x, the equation is
y = k/x where k is a constant
We work out the value of k by using the information y = 6 and x = 5
6 = k/5
k = 30
Hence, the maximum number of tickets when the price is $3 is
y = 30/3
y = 10 tickets
Plug -8 in for x:
4(-8) + 5
solve:
-32 + 5
-27
