Answer:
eric=12
bill=16
Step-by-step explanation:
you can solve this using two simple algebraic equations. this is the key I will be using:
x=bill
y=Eric
x+y=28
x=y+4
since x is by itself in the second equation, I can replace the x in the first equation with y+4
(y+4)+y=28
subtract 4 from both sides
y+y=24
which is also 2y=24
divide both sides by two.
y=12
so now we know Eric is 12 years old.
using this, we can replace the "y" in the second original equation (x=y+4)
x=12+4
x=16
Bill is 16 years old.
