David is 3 years older than Justin. In 4 years, David will be one and a half times as old as Justin. How old is David now?
j = d-3
d+4 = (3/2)(j+4)
plug in j and solve for d.
To solve this problem, let's represent Justin's age as "x" and David's age as "x + 3" since David is 3 years older.
In 4 years, David will be "x + 3 + 4" and Justin will be "x + 4". According to the problem, David will be one and a half times as old as Justin.
So, we can write an equation:
(x + 3 + 4) = 1.5(x + 4)
Now, let's solve the equation:
x + 7 = 1.5x + 6
Subtracting "x" from both sides:
7 = 0.5x + 6
Subtracting 6 from both sides:
1 = 0.5x
To isolate "x", multiply by 2:
2 = x
Therefore, Justin's age is 2 years old.
To find David's age, substitute the value of "x" into the expression "x + 3" that represents David's age:
David's age = 2 + 3 = 5
Hence, David is currently 5 years old.