The number of postage stamps in John’s collection is 27.
We have given that,
John, Johan, and Jonathan collect postage stamps. Johan and Jonathan have the same number of stamps.
<h3>What is an elimination method?</h3>
The elimination method is the process of eliminating one of the variables in the system of linear equations using the addition or subtraction methods in conjunction with the multiplication or division of coefficients of the variables.
Johan and Jonathan have the same number of stamps.
Let x be the Johan and Jonathan postal stamps.
Let y be the John postal stamps.
Two times Johan’s collection is eleven less than five times John’s collection.
2x = 5y - 11............(1)
Three times Jonathan’s collection is three less than seven times John’s collection.
3x = 7y - 3............(2)
Multiply equation 1 with 3
3(2x = 5y - 11)
⇒ 6x = 15y - 33.........(3)
Multiply equation 2 with 2
2(3x = 7y - 3)
⇒ 6x = 14y - 6.............(4)
Subtract equation 4 from equation 3
⇒ 6x - 6x = 15y - 33 - (14y - 6)
⇒ 0 = y - 27
⇒ y = 27
Hence, the number of postage stamps in John’s collection is 27.
Find more information about the elimination method here
brainly.com/question/13877817
#SPJ1