Three-digit Number

[nycmathguy]

In a 3-digit number, the hundreds digit is 4 more than the units digit and the tens digit is twice the hundreds digit. If the sum of the digits is 12, find the 3 digits. Write the number.

 

[MathLover1]

yes

 

[nycmathguy]

yes

Wonderful. I like these high school algebra word problems.

 

[Country Boy]

Aaargh! I have to:
x+ 4+ 2(x+ 4)+ x= 12
x+ 4+ 2x+ 8+ x= 12
4x+ 12= 12
4x= 0
x= 0

x= 0 is the units digit, 2(x+ 4)= 2(4)= 8 is the tens digit, and x+ 4= 4 is the hundreds digit.
The three digit number is 480.

Check: the hundreds digit, 4, is four more than the units digit, 0. The tens digit, 8, is twice the hundreds digit, 4. The sum of the digits is 4+ 8+ 0= 12.

 

[nycmathguy]

Aaargh! I have to:
x+ 4+ 2(x+ 4)+ x= 12
x+ 4+ 2x+ 8+ x= 12
4x+ 12= 12
4x= 0
x= 0

x= 0 is the units digit, 2(x+ 4)= 2(4)= 8 is the tens digit, and x+ 4= 4 is the hundreds digit.
The three digit number is 480.

Check: the hundreds digit, 4, is four more than the units digit, 0. The tens digit, 8, is twice the hundreds digit, 4. The sum of the digits is 4+ 8+ 0= 12.

I will show my work after the rapture of the church.