Mathematics

Grade6

Easy

Question

# Find the value of 5x^{2} if x = - 1

- 4
- 2
- 5
- 6

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 a fixed value. It takes value as per the given conditions. It is generally denoted by an alphabet. A constant is a quantity with a fixed value. In this question, the variable is assigned value -1. After substituting the value we have to perform operation. And, after the operation we will get final value.

## The correct answer is: 5

### The given expression is 5x^{2}.

In this question, the variable is assigned some value. We have to substitute the given value in the above equation and then we have to perform the given operation. After performing all the given operations we will get the final value.

The value assigned to the variable is -1. We have to replace x by -1. After substituting the value, we get the equation as follow:

5x^{2 }= 5(-1)^{2}

Now have to solve it further. In the above equation, -1 is raised to 2. It means we have to multiply -1 by itself. In other words, we have to take -1 twice. The multiplication of two negative numbers gives us a positive number. Therefore, the equation becomes:

5x^{2} = 5(1)

5x^{2} = 5

Therefore, the value of the given expression is 5. So, option (c), which is '5' is the right answer.

^{2 }= 5(-1)

^{2}

Now have to solve it further. In the above equation, -1 is raised to 2. It means we have to multiply -1 by itself. In other words, we have to take -1 twice. The multiplication of two negative numbers gives us a positive number. Therefore, the equation becomes:

5x

^{2}= 5(1)

5x

^{2}= 5

Therefore, the value of the given expression is 5. So, option (c), which is '5' is the right answer.