This can be solved algebraically, that is with defining a variable. This has to be done, if required.
Let n be the number, then 4n + 5 = 25.
4n = 25
n = 5
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But if it was a multiple choice test question, or if just an answer was required, arithmetic approach can be faster.
Given: 5 more than four times a number is equal 25, then ("without" 5, 25 - 5)
four times a number is equal 20, then ("each", 20 / 4)
the number is 5
If you could do both, reasoning and calculations, with mental Math (without writing), that would be the fastest way to get the answer.
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Lastly, if it was a multiple choice, you can try each choice number, take it four times, make it 5 more, and see whether that equals to 25.
