Mathematics

Grade6

Easy

Question

# Find the following expression with the values of x = 1 and y = 2

2xy + 2y – 9

- -1
- - 2
- -3
- 4

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, value is assigned to the variables. We have to perform the required operations and find the final value.

## The correct answer is: -1

### The given expression is 2xy+2y-9.

There are two variables and three constants in the above expression. The variables are: ‘x’ and ‘y’. Values assigned to the variables are x = 1 and y = 2. We have to substitute these values and find the final value of the expression.

There are three terms in the above expression. The first term is '2xy'. It means we have to multiply x and y. And then we have to multiply the value by a constant 2.

In the second term, the variable y is multiplied by 2.

The third term is constant 9. But there is '-‘ sign before it. It means we have to subtract 9 from the whole value we get.

We have to first substitute the value and perform the required operations.

To substitute the value, we have to replace x by 1 and y by 2. After substituting the value, we will get the following equation:

2xy+2y-9 = 2(1)(2)+2(2)-9

We will perform the multiplications first

2xy+2y-9 = 4+4-9

2xy+2y-9 = -1

Therefore, the value of equation is -1

So option (a), which is ‘-1’ is the right option.

We have to be careful about the operations because of the variables. We have to follow the proper procedure for performing the operations. The variables take different values under different conditions. So we have to be careful while substituting the values. The main part of this type of question is just replacing the variables by their values and performing the operation.