Start by setting up a chart based on age now
and age in 5 years for Sally and Kaden.
Since Kaden is 18 years older than Sally, use x for
Sally's age now and x + 18 for Kaden's age now.
If Sally's age now is x, her age in 5 years will be x + 5.
In the same way, Kaden's age in 5 years will be x + 18 + 5 or x + 23.
Now that your chart is filled out, read through the
second sentence in the problem to set up the equation.
Reading the second sentence, we start with "In 5 years" which tells us we will be using the information in the second column of our chart to set up the equation.
So in 5 years, Kaden, x + 23, was, equals,
3 times as old as Sally, 3(x + 5).
So we have the equation x + 23 = 3(x + 5).
First distribute the 3 through both terms inside the set
of parentheses to get 3x + 15.
So we have x + 23 = 3x + 15.
Now subtract x from both sides to get 23 = 2x + 15.
Now subtract 15 from both sides to get 8 = 2x.
Dividing both sides by 2, we find that 4 = x.
Now go back up to your chart and you should be able to recognize
that Sally's age now is 4 years old.
Now, Kaden's age is right below it and his age would be
x + 18 which would be (4) + 18 or 22.
So Sally is 4 years old now.