SOLUTION: Find a two digit number such that three times the tens digit is 2 less than
twice the units digits and twice the number is 20 greater than the number
obtained by reversing the di
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twice the units digits and twice the number is 20 greater than the number
obtained by reversing the di
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Question 1163926: Find a two digit number such that three times the tens digit is 2 less than
twice the units digits and twice the number is 20 greater than the number
obtained by reversing the digits Found 5 solutions by Edwin McCravy, AnlytcPhil, greenestamps, MathTherapy, josgarithmetic:Answer by Edwin McCravy(20060) (Show Source):
I won't do yours for you but I'll do one exactly like it, step by step. You
can use it as a model to do yours by.
So instead of your problem, I'll do this one:
Find a two digit number such that six times the tens digit is 8 less than
four times the units digits, and three times the number is 23 greater than the
number obtained by reversing the digits.
The tens digit is t
The units digit is u
The number is 10t+u
The number obtained by reversing the digits is 10u+t
(1) 6t = 4u - 8
(2) 3(10t+u) = (10t+u) + 23
Simplify the equation (2)
30t + 3u = 10u + t + 23
Subtract 10u from both sides
30t - 7u = t + 23
Subtract t from both sides
(3) 29t - 7u = 23
Now solve equation (1) for t
(1) 6t = 4u - 8
Divide both sides by 6
(4) t = (4u-8)/6
Substitute in equation (3)
(3) 29t - 7u = 23
29(4u-8)/6 - 7u = 23
Multiply through by 6
29(4u-8) - 42u = 138
116u-232 - 42u = 138
74u - 232 = 138
Add 232 to both sides
74u = 370
Divide both sides by 74
u = 5
Substitute in equation (4)
(4) t = (4u-8)/6
t = [4(5)-8]/6
t = [20-8]/6
t = 12/6
t = 2
So t = tens digit = first digit = 2
and u = units digit = second digit = 5
So the two digit number is 25.
Now use this as a model to do yours by.
Edwin
Here is a very different method for solving the problem....
Let t and u be the tens and units digits, respectively. Then we are told
Solve that single equation for t and use logical reasoning to find possible values for t and u, knowing that they are both positive single-digit integers.
Since t has to be a positive integer, and since 2 is not divisible by 3, (u-1) must be positive and divisible by 3.
That means there are only two possible values for u: 4 and 7.
That in turn leads to only two possible values for the 2-digit number: 42 and 74.
Only one of those satisfies the other condition of the problem.
You can put this solution on YOUR website! Find a two digit number such that three times the tens digit is 2 less than
twice the units digits and twice the number is 20 greater than the number
obtained by reversing the digits
Let tens and units digits, be T and U, respectively
Then we get:
12T - 8U = - 8 ------- Multiplying eq (i) by 4 ------ eq (iii)
7T = 28 ------ Subtracting eq (iii) from eq (ii)
Tens digit, or
3(4) - 2U = - 2 ------- Substituting 4 for T in eq (i)
12 - 2U = - 2
- 2U = - 14
Units digit, or
You can put this solution on YOUR website! Using variables t for the tens digit ad u for the units digit, the description is written as ;
and you want to calculate what is .
.
.