Answer:
Bill is 25 years old and Jenny is 29 years old
Explanation:
Systems of Equations:
J = 4 + B
J + B = 54
Substitute J into the first equation.
4 + B + B = 54
Add like terms.
4 + 2B = 54
Isolate the variable.
4 + 2B = 54
-4 -4
2B = 50
2B/2 = 50/2
B = 25 years old
Plug in B into the second equation of the system.
J + B = 54
J + 25 = 54
Isolate the variable.
J + 25 = 54
-25 -25
J = 29 years old
Check your answer. Pick whatever equation in the system and plug in your answers.
J = 4 + B
29 = 4 + 25
29 = 29