Answer
Bill Gates income at that time was \$81 billion and Warren Buffets earned \$67 billions.
Work Step by Step
This problem uses a system of equations.
The first is the combination of y (Bill Gates) and x (Warren Buffet's). And the sum is \$148 billion dollars. This is mathematically written $x+y=148$.
We are also told that Bill Gate's net worth was $x+14$
We can derive two equations from this information and the original equation, using the relationship $y= x+14$:
$$ x + x+ 14 = 148$$
$$ 2x + 14 = 148$$
Subtract by 14 on both sides, which gives
$$2x+ 14 -14 = 148 - 14$$
$$2x= 134$$
Divide by 2
$$x= \frac{134}{2}$$
$$ x= 67$$
To get the value of y, use the original equation, $x+y=168$.
$$y + 67 = 168$$
Subtract 67 from both sides.
$$y + 67 -67 = 168 -67 $$
y= 81
This the answer is: Bill Gates income at that time was \$81 billion and Warren Buffets earned \$67 billions.