You can put this solution on YOUR website! a number decreased by -13 is the same as a number increased by 13.
let x be the number.
you get x - (-13) = x + 13
the result of that is equal to 15 * the number.
that becomes x + 13 = 15x
subtract x from both sides of that equation to get 13 = 14x
solve for x to get x = 13/14.
x + 13 becomes 13/14 + 13 = 13.92857143.
15 * 13/14 = 13.92857143.
they're equal as they should be.
your solution is that the numcber is equal to 13/14.
that's what i get.
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