exploring mathematics elementary algebra....the sum of the digits of a two-digit number is 12. the value of the number is equal to 11 times the tens digit. find the number.
Math - Writeacher, Thursday, January 6, 2011 at 10:14pm
tres ninos school - Reiny, Thursday, January 6, 2011 at 10:28pm
let the unit digit be x
let the tens digit be y
so the "value" of the two digit number is 10y + x
and then you said:
10y + x = 11y
x = y
but we also know x+y = 12
mmmh? Can you think of two numbers that are equal and add up to 12 without doing the algebra?