What is 9x for x = 4
The Correct Answer and Explanation is :
To solve for ( 9x ) when ( x = 4 ), you simply substitute ( 4 ) into the equation:
[
9x = 9 \times 4
]
Calculating that gives:
[
9 \times 4 = 36
]
Thus, ( 9x = 36 ) when ( x = 4 ).
Explanation
In mathematics, variables like ( x ) represent unknown values that can change depending on the context. In this case, we are given a specific value for ( x ) (which is ( 4 )). The expression ( 9x ) indicates that we are multiplying the value of ( x ) by ( 9 ).
Multiplication is one of the basic arithmetic operations and can be thought of as repeated addition. For example, multiplying ( 9 ) by ( 4 ) means we are adding ( 4 ) a total of ( 9 ) times:
[
4 + 4 + 4 + 4 + 4 + 4 + 4 + 4 + 4 = 36
]
This is a useful way to visualize multiplication, especially when teaching or learning basic math concepts.
The result of ( 36 ) has various implications depending on the context in which ( 9x ) is used. For instance, if ( x ) represents hours worked, ( 9x ) could signify total pay at a rate of ( 9 ) units per hour, resulting in ( 36 ) units of currency for ( 4 ) hours of work. In another scenario, if ( x ) represents a quantity of items, ( 9x ) could represent the total number of items produced when producing ( 4 ) batches of ( 9 ) items each.
Understanding how to manipulate variables and equations like this is fundamental in mathematics, as it lays the groundwork for more complex algebraic concepts and real-world applications. Thus, solving for ( 9x ) with a given ( x ) is a practical skill that can be applied in many different fields.