Answer:
Jane have $25
Frank have $100
Scott have $19
Step-by-step explanation:
To find the amount that each have, we have to represent this information in a mathematical format  and then solve
let x represent represent the amount that Jane has
let Y represent represent the amount that Frank has
let z represent represent the amount that Scott has
From the question given, "Jane, Scott, and Frank have a total of $144"  can be represented mathematically as
x + y + z = $144 ---------------------------------------------------------------------------------(1)
 "Frank has 4 times what Jane has"   can be represented mathematically as 
y = 4x ---------------------------------------------------------------------------------------------(2)
"Scott has $6 less than Jane"  can be represented mathematically as 
z= x- 6 ----------------------------------------------------------------------------------------------(3)
we can now solve the equations using the substitution method
substitute equation (2)  and (3)  into equation (1)
x + y + z = $144 
x + 4x + x-6 = $144
6x -6 = $144
add 6 to both-side of the equation
 6x - 6 + 6 = $144 + 6
6x =$150
Divide both-side of the equation by 6
6x/6 = 150/6
x = $25
from equation 2
y = 4x 
substitute x= $25 in equation (2)
y = 4 (25)
y = $100
substitute x=$25 in equation  (3)
z = x- 6
z = 25 - 6
z=$19
Jane have $25
Frank have $100
Scott have $19