Mathematics
Grade6
Easy
Question
5x + 2 – 4x + 1
- x + 3
- x + 4
- 9x + 1
- x
Hint:
This is an algebraic expression. An algebraic expression consists of two components: a variable and a constant. A variable is a quantity that doesn’t have any fixed value. It takes value according to the conditions. It is denoted by the alphabet. A constant is a quantity with a fixed value. In this question, we are given an expression. We have perform the required operations and find the final value.
The correct answer is: x + 3
The given expression is 5x + 2 – 4x + 1.
There is one variable and 4 constants in the above expression. The variable is: 'x'. There are four terms in the above expression. We have to perform the operations between them and find the right answer.
If we see, the first and third terms contain the same variable. And the second and fourth terms are constant. Such terms with the same variables or no variables are called “like terms.” And the terms with different variables are called “unlike terms.”
For like terms, we can perform the operations between their coefficients by keeping the variable constant. It means we can treat each term as a constant and perform operations like normal operations on constants.
For the above expression, we can perform an operation between the first and third terms as they have the same variable ‘x’. And the second and fourth terms are constants, so we can perform the operation directly.
Let’s rearrange the terms to bring the like terms together.
5x + 2 – 4x + 1 = 5x – 4x + 2 + 1
5x + 2 – 4x + 1 = (5x - 4x ) + (2 + 1)
For first bracket, we will keep x constant and subtract 4 from 5. For second bracket we have to add 2 and 1.
5x + 2 – 4x + 1 = x + 3
Therefore, the value of the equation is x + 3.
So option which is ’x + 3’, is the right option.
We have to be careful about different types of variables. Only like terms operate with each other.
