Expert: Lynn Houston - 1/21/2010

Question
please tell me how to solve this question...I am helping my daughter with her math home work..I never learned this

12.42 / (17 -n) =4.14    N=?

Answer
To solve this, you have to "undo" everything that has been done to N.  Start by getting rid of the fraction, by multiplying both sides of the equation by 17-n

12.42(17-n)/(17-n) = 4.14(17-n)  on the left side the 17-n cancels out

12.42 = 4.14(17-n)  multiply both 17 and n by the 4.14
12.42 = 70.38 - 4.14n  add 4.14n and subtract 12.42 from both sides
4.14n + 12.42- 12.42 = 70.38 - 4.14n + 4.14n - 12.42
4.14n = 57.92, finally, divide both sides by 4.14
n = 14

To test your answer, insert 14 for n into the original equation