In eight years, peter will be three times old as he was eight years ago, how old is peter now?
Divide both sides by
Peter is 16 years old now.
Since you're only dealing with Peter's age at various points in time, you will only need to write one equation.
Let's say that Peter's age is
If you take Peter's age eight years from now to be
#x+8 = 3 * (x-8)#
Solve this equation for
#x + 8 = 3x - 24#
#2x = 32 implies x = 32/2 = color(green)(16)#
So, eight years ago Peter was 8. Eight years from now, which is equivalent to 16 years from when he had 8 years, he will be 24.
Peter is currently
Let's represent peter's age by the variable
In eight years Peter will be
Eight years ago Peter was
The problem says that
Now, we just solve this equation for
Hence, Peter is currently