How To Delete Off Sd Card

Zadanie nr9

For which values \u200b\u200bof a and b, the number of the same seven digits 213a54b is divisible by 45?

solution to the problem:
number is divisible by 45, if it is divisible by 9 and features 5.Z number divisible by 9 (the number is divisible by 9 if the sum of its digits creates a number divisible by 9) we obtain the condition: the number of 2 +1 + 3 + 4 + 5 and b = a + b is 15 9.Z divisible by the number of features divisible by 5 (the number is divisible by 5 if its last digit is 0 or 5) indicates that b = 0 or b = 5
For b = 0 we obtain a 15 is divisible by 9, and? <0;9>, the numbers in the range <0+15;9+15>? <15;24> number divisible by 9 is the number 18, ie a = 3
For b = 5 we get: a 20 is divisible by 9, the numbers in the range <0+20;9+20>? <20;29> number divisible by 9 is the number 27, ie a = 7
Answer: For a = 3 b = 0 and a = 7 and b = 5 as the number is divisible by 213a54b 45th