Answer:
Daniel=13.
Step-by-step explanation:
We can use the given information to write down two equations that describe the ages of Ben and Daniel.
Let Ben's current age be b and Daniel's current age be d.
The information in the first sentence can be expressed in the following equation:
Three years ago, Ben was b−3 years old, and Daniel was d−3 years old.
The information in the third sentence can be expressed in the following equation:
Now we have two independent equations, and we can solve for our two unknowns.
Because we are looking for d, it might be easiest to use our first equation for b and substitute it into our second equation.
Our first equation is: b=d+20. Substituting this into our second equation, we get the equation:
which combines the information about d from both of our original equations.
Simplifying both sides of this equation, we get: d+17=3d−9.
Solving for dd, we get: 2d=26.
d=13.
