Question

In a two digits number the digit at the unit place is double the digital in the place the number it's digit are reversed find the number.

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Answer 1

Answer:

Problem 1 Two of the following systems of equations have solution (1;3). Find them out by checking.

a) \displaystyle \begin{array}{|l} x + y = 5 \\ 2x - y = 7; \end{array}

x+y=5

2x−y=7;