Answer:
Let Luke be represented as L , rachel be represented as R and daniel be represented as D
As per the statement: Luke has $21 more than rachel and $48 more than daniel
⇒[tex]L = 21 +R[/tex] and L = 48+D
equate these two we get;
21 + R = 48 + D
we can write this as;
R = 48+D -21
R = 27 +D ......[1]
Also, it is given that altogether they have $168.
⇒[tex]L+R+D = 168[/tex] .....[2]
Substitute the value of L=21+R in equation [2] we have;
[tex]21+R+R+D= 168[/tex]
Combine like terms;
[tex]21+2R+D= 168[/tex]
Subtract 21 from both sides we get;
2R+D= 147 ......[3]
Substitute the value of equation [1] in [3] we get;
2(27+D)+D = 147
Using distributive property; [tex]a\cdot (b+c) = a\cdot b +a\cdot c[/tex]
54 + 2D +D = 147
Combine like terms;
54 +3D =147
Subtract 54 from both sides we get;
3D = 93
Divide both sides by 3 we get;
D = $31
Now, substitute this value of D in L = 48+D we have;
L = 48 + 31 = $79
Therefore, $79 does Luke have.