Respuesta :
433 stamps were in collection at the end of 2018.
What is a linear equation?
'A linear equation is an equation in which the highest power of the variable is always one. It is also known as a one-degree equation.'
According to the given problem,
We know,
y = mx + c, where m = constant rate of change,
c = value of the y-intercept.
Let x = number of years after 1932.
y = Number of stamps after x years.
In 1972 (year 40), there were 203 stamps in the collection.
⇒ 203 = 40m + c (1) [rate of change in number of stamps is constant]
In 2009 (year 77), there were 383 stamps in the collection.
⇒ 383 = 76m + c (2)
Now, for solving the equations, Subtracting (1) from (2)
⇒ 180 = 36m
⇒ m = 5
⇒ 5 stamps added per year.
Now for the value of c, putting the value of m in equation (1)
⇒ 203 = 40m + c
⇒ 203 = (40 × 5) + c
⇒ c = 203 - 200
⇒ c = 3
Stamps in 2018 (year 87) = 87m + c
= (5 × 86) + 3
= 430 + 3
= 433
Hence, we can conclude that 433 stamps were in collection at the end of 2018.
Learn more about linear equation here: https://brainly.com/question/11897796
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