y is directly proportional to the square of x. given that y = 50 when x = 5, find the value of y when x = 3​

y = 18

Step-by-step explanation:

Given y is directly proportional to x² then the equation relating them is

y = kx² ← k is the constant of proportion

To find k use the condition y = 50 when x = 5

50 = k × 5² = 25k ( divide both sides by 25 )

2 = k

y = 2x² ← equation of proportion

When x = 3 , then

y = 2 × 3² = 2 × 9 = 18

the total estimated nappy use.=10,500,000

step-by-step explanation:

given that on an average the average baby uses 3528 napkins.

in a particular year 2014, the number of births were 299697 in new south wales.

rounding off the number of births to the nearest hundred thousand we have

no of birtsh = 300000

also rounding off the average usage to nearst thousand we get

average use of a baby = 3500

hence total number of nappy estimated to be used = 3500x300000

= 10,500,000

answer is 10,500,000 nappies