SOLUTION: a two digit number is 4 times the sum of its digits, if the number is doubled and then decreased by 12, the result is the number with the digits reversed. what is the number?

Algebra.Com
Question 481455: a two digit number is 4 times the sum of its digits, if the number is doubled and then decreased by 12, the result is the number with the digits reversed. what is the number?
Answer by ankor@dixie-net.com(22740)   (Show Source): You can put this solution on YOUR website!
Let x = the 10's digit, Let y = units
then
10x+y is the two digit number
and
10y+x is the number reversed
:
Write an equation for each statement:
:
"two digit number is 4 times the sum of its digits,"
10x + y = 4(x+y)
10x + y = 4x + 4y
10x - 4x = 4y - y
6x = 3y
Simplify, divide both sides by 2
2x = y
:
"if the number is doubled and then decreased by 12, the result is the number with the digits reversed.
2(10x+y) - 12 = 10y + x
20x + 2y - 12 = 10y + x
20x - x = 10y - 2y + 12
19x = 8y + 12
Replace y with 2x (from the 1st equation)
19x = 8(2x) + 12
19x = 16x + 12
19x - 16x = 12
3x = 12
x = 4 is the 10's digit
and
y = 2(4)
y = 8 is the units
therefore
48 is the number
:
You can confirm this by using 48 as the number in both statements

RELATED QUESTIONS

A two digit number is six times the sum of its digits. If the digit in the units’ place (answered by stanbon)
The sum of the digits of a two-digit number is 9. If the number is doubled, then... (answered by ankor@dixie-net.com,solver91311)
A two digit number the sum of its two digits is three times of its units digit and its... (answered by Theo)
A number is doubled and then decreased by 12. The result is 56. What is the original... (answered by rfer)
A two-digit number is 11 times its units digit. The sum of the digits is 12. Find the... (answered by bucky)
a two digit number is 11 times its units digit. The sum of the digits is 12. find the... (answered by gwendolyn,Alan3354)
A two digit number is seven times the sum of its digits. if each digit is increased by... (answered by josgarithmetic)
If the value of a two digit whole number is three times the sum of its digits, then the... (answered by ankor@dixie-net.com)
The unit digit of a two digit number is 1 less than the tens digit. If the number is... (answered by ikleyn)