Just looking for some guidance on the following problem:
Find the least value of n (Natural number) for which (5n + 3 / 7 - n) < 1, n <> 7
5n + 3 < 7 - n
6n + 3 < 7
6n < 4
3n < 2
n < 2/3
Since n is a Natural number we get n = 0 as the least value
The 1st step above involves multiplying across by 7 - n, however 7 - n is negative for n > 7 so this would equate to multiplying an inequality by a negative number in which case the sign would have to be changed.
Is it valid to multiply across by 7 - n as described?