SOLUTION: the difference between the tens digit and the unit digit of a two digit number is 3. Suppose the tens digit is one less than twice the units digit. what is the number?
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Question 451650: the difference between the tens digit and the unit digit of a two digit number is 3. Suppose the tens digit is one less than twice the units digit. what is the number? Answer by nerdybill(7384) (Show Source):
You can put this solution on YOUR website! the difference between the tens digit and the unit digit of a two digit number is 3. Suppose the tens digit is one less than twice the units digit. what is the number?
.
Let x = tens digit
and y = units digit
then
from: "the difference between the tens digit and the unit digit of a two digit number is 3"
x-y = 3 (equation 1)
from: "Suppose the tens digit is one less than twice the units digit"
x = 2y-1 (equation 2)
.
Start with equation 1:
x-y = 3
substitute definition of x from equation 2:
2y-1-y = 3
y-1 = 3
y = 4
.
Substitute above into equation 1 to find x:
x-y = 3
x-4 = 3
x = 7
.
Solution: the number is 74
