Answer:
x represents Sally's age. y represents Thomas's age.
x + 2y = 12
x –y = 3
Step-by-step explanation:
Solve by substitution. Rewrite the second equation to get a value for x.
x -y = 3 Add y to both sides so it becomes x = y+3
Substitute in place of x in the first equation.
x + 2y = 12 becomes
(y + 3) + 2y =12. Combine like terms.
3y + 3 = 12 Subtract 3 from both sides
3y = 12 –3
3y = 9 Divide both sides by 3
y = 3 Tomas
Substitute for y, solve for x
x + 2(3) = 12
x + 6 = 12 Subtract 6 from both sides.
x = 6 Sally
