the sum of a two digit number and the number formed by interchanging its digit is 110 if 10 is subtracted from the first number, the new number is 4 more than 5 times the sum of the digit in the first number . the first number is....
Answers
A 2 digit no means it has 2 unit places, THE ONE'S PLACE AND THE TEN'S PLACE!
if u take a 2 digit no, for instance 78
when u expand it..7×10+8×1
we apply the same thing in the above question...
Let the no in the one's place be x and the ten's place be y...therefore the no will be 10y+x
Now moving further...they hav given the sum of the 2 digit no...that means y+x
Now moving further...they hav given no formed after interchanging the digits...that means if we take 78...we shift the digits and make it 87..so we use the same concept in here too..
therefore the new no formed is 10x+y
now lets solve the sum....
the sum of a 2 digit no and the no formed after interchanging the values...which means
(y+x)+(10x+y)=110
y+y+x+10x=110
2y+11x=110.....(i)
10-(10y+x)=4+5(y+x)
10-10y-x=4+5y+5x
10-4=10y+5y+x+5x
6=15y+6x
15y+6x=6.....(ii)
now we can solve it with elimination method
we can multiply eq(i) with 6 and eq(ii) with 11
》12y+66x=660
》(-)165y+(-)66x=(-)66
-153y=594