Answer:
Alvin 46, Elga 23
Explanation:
So you set up two equations:
Before anything lets assume
age of Elga= E
age of Alvin= A
Then,
A= 2E (Alvin's age is 2x Elga's age) (EQ 1)
A+E=72 (Sum of Alvin's and Elga's age) (EQ 2)
Plug the value of A from eq1 to eq2.
A+E=72
2E+E=72 (we plugged here the value of A from eq1)
3E=72
E= 26 (Elga's Age)
Now solve for Alvin's age by plugging E in either equation:
A+E=72
A+26=72
A= 46yr (Alvin's Age)
or Plug in eq 1
A=2E
A= 2x23= 46yr (Alvin's Age)