Let the number of children be x.
Cost for each child = $4, total = 4*x = 4x
Let the number of adults be y.
Cost of each adult = $6, total = 6*y = 6y
Total = 4x + 6y = 26
4x + 6y = 26 Divide both sides by 2.
2x + 3y = 13
By inspection, x could be 2, and y could be 3.
2x + 3y
2*2 + 3*3 = 4 + 9 = 13
So there could have been 2 children and 3 adults.
There could have also been 3 adults and 2 children
Hope this helps.
