Select the correct answer.
Find the value of [tex]h(-7)[/tex] for the function below.
[tex]h(x)=5.7-19 x[/tex]
A. -127.3
B. 0.67
C. -138.7
D. 138.7
Answer (1)
Substitute x = − 7 into the function h ( x ) = 5.7 − 19 x .
Calculate − 19 × − 7 = 133 .
Add 5.7 + 133 = 138.7 .
The value of h ( − 7 ) is 138.7 .
Explanation
Understanding the problem We are given the function h ( x ) = 5.7 − 19 x and we need to find the value of h ( − 7 ) . This means we need to substitute x = − 7 into the function and calculate the result.
Substituting the value Substitute x = − 7 into the function: h ( − 7 ) = 5.7 − 19 ( − 7 ) Now, we need to perform the multiplication and subtraction.
Performing the calculation First, calculate the product of − 19 and − 7 :
− 19 × − 7 = 133 Now, substitute this back into the equation: h ( − 7 ) = 5.7 + 133 Finally, add the two numbers:
Finding the final value 5.7 + 133 = 138.7 So, the value of h ( − 7 ) is 138.7 .
Selecting the correct answer Comparing our calculated value with the given options, we see that option D is the correct answer.
Examples
Imagine you are tracking the temperature change in a science experiment. The function h ( x ) = 5.7 − 19 x could represent the temperature at time x , where 5.7 is the initial temperature and − 19 is the rate of change per unit of time. Finding h ( − 7 ) would tell you the temperature 7 units of time in the past. This kind of calculation is useful for predicting or understanding trends based on a linear model.
