the sum of the digits of a two digit number is 12 if 18 added to it the digits are reversed find the number
Answers
Answer:
57
Step-by-step explanation:
Let us call a the tens digit and b the units digits. The permitted values for a are 1 to 9; for b, 0 to 9. The sum of the digits is
a + b = 12;
The requested number is therefore
N = 10a + b;
and the number formed by reversing the digits is
M = 10b + a.
If you add 18 to N, you get M, that is, in algebraic form:
N + 18 = M;
or, using the last expressions for N ad M,
10a + b + 18 = 10b + a;
by subtracting a and b from both terms, we get
10a +b + 18 – a – b = 10b + a – a – b;
9a + 18 = 9b;
and, by dividing both terms by 9, we get
a + 2 = b.
By replacing this value for b in the first equation, we get
a + b = a + a + 2 = 2a + 2 = 12
that is, by subtracting 2 from both terms,
2a = 10
or
a = 5;
b = a + 2 = 7.
The requested number is therefore
N = 57.
In fact, if you add 18 to it, you get 57 + 18 = 75, which has the same digits in reversed order.
Please Mark me As Brainliest