Question

If \[x\] is equal to \[41\] and \[y\] is equal to \[3\] , then what is the value of \[x - 9y\]?

Answer 1

Hint: An expression is a composite entity formed by combining variables and constants using various mathematical operations. In Mathematics, we mainly have four basic operations: addition, subtraction, multiplication, and division. These can be performed on numbers and algebraic expressions.

Complete step-by-step answer:
Variable: A variable is an entity whose value is not fixed; it can vary. Variables are generally denoted by the letters \[x,y,z\] , etc.
Constant: A constant is an entity whose value is fixed for the given situation. The value of the constant might be unknown, but we know that it is fixed. Constants are generally denoted by the letters \[a,b,c\] , etc. if their values are not known or not provided, and by specific numerical values like\[29,\pi \] , etc. if their values are known.

An expression is a composite entity formed by combining variables and constants using various mathematical operations. In Mathematics, we mainly have four basic operations: addition, subtraction, multiplication, and division. These can be performed on numbers and algebraic expressions. The addition and subtraction of algebraic expressions is almost similar to the addition and subtraction of numbers.
While adding and subtracting algebraic expressions, we first categorize the terms into two types - like and unlike terms. The terms whose variables are the same are known as 'like terms' and the terms having different variables are 'unlike terms'. The like terms are combined and then simplified. Unlike terms cannot be combined by adding or subtracting.

While subtracting one algebraic expression from another, we need to be careful with the signs. It should be noted that if there’s a subtraction sign before the brackets, we need to reverse all the signs once we open the brackets.
Here in this question we are given values \[x = 41\] and \[y = 3\].
We are to find the value of \[x - 9y\].
Putting the given values we get
\[x - 9y = 41 - 9(3) = 23\]
So, the correct answer is “23”.

Note: It is always better to subtract two expressions at one time. Do not try to subtract three or more expressions together through the column method. In case there is a negative sign outside the brackets, operators inside the brackets need to be changed.