SOLUTION: Solve by system of equations.
The sum of the digits of a two digit number is 14. If 4 is added to the number, the result is 7 times the units digit. Find the number.
so far i h
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The sum of the digits of a two digit number is 14. If 4 is added to the number, the result is 7 times the units digit. Find the number.
so far i h
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Question 380468: Solve by system of equations.
The sum of the digits of a two digit number is 14. If 4 is added to the number, the result is 7 times the units digit. Find the number.
so far i have
x+y=13 y=13
show all work please Answer by solver91311(24713) (Show Source):
Let represent the 10s digit and let represent the 1s digit.
The sum of the digits is 14, so:
Which we will find it convenient to express:
The number itself must be:
(Think about it -- the number 42 is 4 times 10 plus 2, right?)
4 added to the number is 7 times the 1s digit:
and we will find it convenient to write this as:
Now, using the alternative expression of the first equation we can substitute an expression in for in the above equation, thus:
A little manipulation gets us to:
Solve that for and then substitute back into the original first equation to determine the value of x. Put the two digits together to create the desired two digit number.
John
My calculator said it, I believe it, that settles it
