When positive integer A, which has n digits, is multiplied by (n+2) , the product is a number with (n+1) digits, all of whose digits are (n+1) . How many instances of A exist?

  A = 95238 (only)

Step-by-step explanation:

The question is equivalent to asking what n-digit number consisting only of the digit n will be divisible by n+1. Of the numbers 1, 22, 333, 4444, ... 999999999, the only one is 666666, which is divisible by 7.

The 5-digit integer A is 666666/7 = 95,238. There is only one instance of A.

whole numbers.

step-by-step explanation:

we are given the average monthly rainfall (in millimeters) model r(m) for the years 1900-2009 as a function of the month number m.

as we can see m is taken for the number of months for years 1900-2009.

we know that number of months can't be a negative number or decimal number or a fraction.

so, the number of months could be only positive whole numbers.

therefore, whole numbers is more appropriate for the domain of r.

it is x=-4

step-by-step explanation: