How to find unknown reduced

How to find unknown reduced

Quite often such equations in which it is unknown reduced meet. For example X - 125 = 782, where - reduced by X, 125 - deductible, and 782 - a difference. It is necessary to make for the solution of such examples with the known numbers a certain set of actions.

It is required to you

  • - handle or pencil;
  • - notebook or sheet of paper.


1. Present that you got 2 kilograms of apples and put them in a basket. Then you ate 3 fruit. And further counted remained and at you it turned out that in a basket 10 apples lie now. After all these manipulations to you there was terribly interestingly what amount of fruit you bought initially?

2. Work out the equation where unknown, i.e. X is amount of the bought fruit, is 3 a number of the eaten apples, and 10 is that it was necessary to lie in a basket. Thus at you such example has to turn out: X - 3 = 10. In this mathematical expression of X is called reduced, 3 - deductible, and the turned-out difference is equal to 10.

3. Now start the solution of the equation. It is known: to find reduced, it is necessary to put a difference with deductible. It turns out that in your case: X = 10 + 3;10 + 3 = 13; Х = 13.

4. Make check, having substituted the turned-out number in the equation. So, X - 3 = 10, you found unknown reduced, i.e. X = 13, thus: 13 - 3 = 10. Expression is right, therefore the equation is solved correctly. Certainly, if you solve the examples consisting of prime numbers, it is optional to carry out check. But when numbers two-place, three-digit, four-digit, etc. appear in the equations, surely check yourself. It will not take away a lot of time, but will give absolute confidence in result of the done work.

Author: «MirrorInfo» Dream Team