Often the equations in which one of composed is unknown meet. To solve such equation, it is necessary to remember and do a certain set of actions with these numbers.
It is required to you
- - sheet of paper;
- - handle or pencil.
Instruction
1. Present that before you you have 8 rabbits only 5 carrots. Think how many carrots you need to buy still that to each rabbit got on carrot.
2. Let's present this task in the equation form: 5 + x = 8. Let's substitute on the place x number 3. Really, 5 + 3 = 8.
3. At addition of number which we put are called composed, and the number received as a result of addition – the sum. The sum has to be better known composed or is equal to it.
4. When you substituted number into place x, you made the same operation, as at subtraction of 5 of 8. So that to find unknown composed, subtract from the sum the known composed.
5. Let's say you have 20 rabbits and only 5 carrots. Let's work out the equation. The equation is an equality which is carried out only at some values of the letters entering it. Letters which values are required to be found are called unknown. Work out the equation with one unknown, call it x. At the solution of our task about rabbits the following equation turns out: 5 + x = 20.
6. Let's find a difference between 20 and 5. At subtraction that number from which subtract is called reduced. That number which is subtracted is called deductible, and the end result is called a difference. So, x = 20 – 5; x = 15. It is necessary to buy 15 carrots for rabbits.
7. Make check: 5 + 15 = 20. The equation is solved truly. Certainly, when it comes to such prime numbers, it is optional to carry out check. However when it is necessary to solve the equations with three-digit, four-digit and to that similar numbers, it is necessary to carry out check to be sure absolutely of result of the work.