Answer:
5
Explanation:
Assuming the n+9 is in the denominator, start by cross multiplying.
multiply the n+9 by 2 and 4 by 7 to form the eqution 2n+18 = 28.
subtract the 18 from both sides to form the equation 2n = 10.
divide both sides by 2 to answer n = 5.
Another method is to think how to create equivalent fractions. to have 4/n+9 equal 2/7, the 2/7 is equivalent to 4/14. that means that n+9 is equivalent to 14, because the numerator are equal to each other. if n+9 = 14, then n = 5.