setup a simple algebraic equation and solve.
5x = 7x-28
-5x -5x
0=2x-28
+28 +28
28=2x
Now divide both sides by 2 and you get that she is 14
Answer:
14yrs
Step-by-step explanation:
Mary’s age=x
5•x = x•7-28
=> 5x-7x= -28
=> -2x= -28
=> x= -28/-2
=> x= 14