Respuesta :

iGreen
Make an equation:

J = 1/2F - 10

Where 'J' represents Justin's age and 'F' represents his Father's age.

Plug in 12 for J:

12 = 1/2F - 10

Add 10 to both sides:

22 = 1/2F

Divide 1/2 to both sides or multiply by its reciprocal, 2:

F = 44
22 because 12 plus 10 is 22, or because 10-12=2  2+20=22  20+2 because 10nis half of 20