The sum of the digits of a 2 digit number is 9. The number formed by reversing the digits is less than the original number by 45. Find the original number.
Answers
Answered by
1
Answer:
72
Step-by-step explanation:
A + B = 9 (Eq. 1)
10A + B -49 =10B + A(2 digits numbers are written in standard form)
9A -45 = 9B
-45 = 9B - 9A
45 = 9A - 9B
45 = 9(A-B)
5 = A -B (Eq. 1)
Adding Eq. 1 and 2
A + B + A - B = 9 +5
2A = 14
A = 7
Substituting in 1
7 + B = 9
B = 2
2 digits numbers are written in standard form
Answered by
1
Step-by-step explanation:
let unit digit=x
tens digit=9-x
original no.=90-x
new no. =10(unit digit)+tens digit
=9x+9
new no. =original +45
9x +9=90-9x +45
18x =36
x=2
given no. =90-9x
=90-18=72
on interchange in =27,72
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