What is 5x, when x= 3?
The Correct Answer and Explanation is:
To find the value of ( 5x ) when ( x = 3 ), we substitute the value of ( x ) into the expression ( 5x ).
Given:
[
x = 3
]
Substitute ( x = 3 ) into the equation ( 5x ):
[
5x = 5(3)
]
Now, perform the multiplication:
[
5(3) = 15
]
Thus, when ( x = 3 ), the value of ( 5x ) is ( 15 ).
Explanation:
This problem involves simple substitution and multiplication. In algebra, substitution means replacing a variable with its known value. In this case, ( x ) is the variable, and we know that ( x = 3 ). We substitute 3 wherever ( x ) appears in the expression.
Once we substitute, the equation becomes ( 5(3) ), which is a multiplication problem. Multiplying 5 by 3 gives us 15.
Multiplication is one of the basic arithmetic operations, and it can be thought of as repeated addition. In this case, multiplying 5 by 3 means adding 5 three times:
[
5 + 5 + 5 = 15
]
This method of repeated addition helps to understand the concept of multiplication, especially for students who are learning these concepts.
In algebra, variables like ( x ) represent unknown values, and equations are used to show relationships between different quantities. Once we substitute known values into an equation, we can solve for the unknowns or find the result of an expression. The value of ( 5x ) when ( x = 3 ) is simply 15, and it demonstrates how basic algebraic principles of substitution and multiplication work together to provide a solution.
In summary, ( 5x = 15 ) when ( x = 3 ).