Question

Luke has $21 more than Rachel and $48 more than Daniel. All together they have $

Answer 1

This can be solve by 3 variable equation
let x be the money of luke
y money of rachel
z money of daniel
first equation
x = y + 21
second equation
x = z + 48
third equation
x + y + z = 168
solving simultaneously
x =79
y = 58
z = 31