Equations and Inequalities in Grade III

Hello friends, Previously we have discussed about is 2 a rational number and in today's article we are going to discuss about the problems in equations and inequalities for grade III of CBSE math Syllabus. Here, I am going to tell you the best way of understanding the equations and inequalities problems. Start with the definition of equation, when two expressions are joined with the help of equal symbol then, it is called as equation. For example: x + 5=2, x + 4=1. Let me clear one thing that when we add, subtract, multiply, or divide the same number on both the side of the equation, the equal sign of an equation does not change. On other hand two algebraic expressions or two real numbers related by the symbol ‘<’, ‘>’, ‘<=’ or ‘>=’ form an inequality. For example: x-3>5. In inequalities perform addition or subtraction by the same number on both sides. Multiply or divide by the same number on both sides but if we divide or multiply by a negative number, we must reverse the inequality sign.
Now I would like to tell you that how would you solve the equations and inequalities problems. Firstly we are going for Problems in equations.
Example: Solve the equation for the variable y: y - 20 = 40
          Solution: y - 20 = 40
         Firstly we add 20 on both sides of the equation
          y – 20 + 20 = 40 + 20
         y = 60
        So, the answer is y = 60.
Example: Solve the equation for the variable: (y/3) + 50 = 40
            Solution :(y / 3) + 50 = 40
           Subtract 50 on both sides of the equation
          (y / 3) + 50 - 50 = 40 - 50
         (y / 3) = -10
        Multiply 3 on both sides of the equation
        (y / 3) * 3 = -10 * 3
        y = -30 so, the answer is 30

Now I am discussing about how to solve inequalities problems. Some examples are given below.(want to Learn more about Inequalities ,click here),
Example: Solve the inequality: 8x + 4 < 6x +7.
Solution: We have, 8x + 4 < 6x +7
Subtract 6x on both sides of the equation
8x – 6x + 4 < 6x + 7 – 6x
2x + 4 < 7
Subtract 4 on both sides of the equation
2x + 4 – 4 < 7 – 4
2x < 3
Divide by 2 on both sides of the equation
x < 3/2
So from the above all the real numbers are greater than 1. Hence, the solution set is (-infinity, 3/2).
Example: Solve the inequality: -2x – 7 < 7
Solution: -2x-7<7
Add 7 on both sides of the equation
-2x - 7 + 7 <7 + 7
-2x < 14
Divide by-2 on both sides of the equation and you will see the inequality sign is to be reversed.
x > -7
So from the above all real numbers are greater than -7 and hence, the solution set is (-7, infinity).

So this is all about equations and inequalities and if anyone want to know about

Time in terms of unit fractions then they can refer to Internet and text books for understanding it more precisely. You can also refer 4th Grade blog to study about Multiplication and division situations.