Question

The sum of Sally's age plus twice Tomas's age is 12. The difference of Sally's age and Thomas's age is 3. Write and solve a system of equation to find their ages. Interpret the solution.

Answer 1

Sally is older because: Sally:6 Thomas:3 Twice Thomas's age is 6. 6+6=12 Equation:6+3x2 or (6+3)x2 hint:PEMDAS Solved:12

Answer 2

s=sally
tomas=t

s+2t=12
s-t=3
add t to both sides
s=3+t
subtitute 3+t for s in first equation
3+t+2t=12
3+3t=12
subtract 3
3t=9
divide by 3
t=3
tomas=3

subsitute
s=t+3
s=3+3
s=6

sally=6
tomas=3