The answer is D, 10. 4 years ago she was 6, so William must have been 1 (1/6 of 6). In 6 years time she will be 16 (10+[4+6 years]).
The answer should be 5/a-a=0
<h3>
Answer: Choice A</h3>
Why? Because the denominators are both the same at 2x+8. We can only add or subtract fractions when the denominators are the same. The general rule for adding fractions is

We have numerators A and B added together over a common denominator C. If we didn't have a common denominator, then we'd have to do a bit of algebraic manipulation to get both fractions to a common denominator. It doesn't have to be the lowest common denominator (LCD), though it's often more efficient that way.
Step-by-step explanation:
use distance equation