Answer:
The age of Madison such that the sum of all three siblings' consecutive age is 78 will be 25 years old.
Explanation:
Determine the known quantities and designate the unknown quantity as a variable while trying to set up or construct a linear equation to fit a real-world application.
suppose Madison's age = x
Second older sister will have age = x + 1
Third older sister will have age = x + 2
Sum, (x) + (x + 1) + (x + 2) = 78
3x + 3 = 78
3x = 75
x = 25
Madison such that the sum of all three siblings' consecutive age is 78 will be 25 years old".