Answer:
The function input is -20 when the output is 25
Step-by-step explanation:
we have
[tex]y=-75-5x[/tex]
where
y is the dependent variable or output
x is the independent variable or input
If the output is 25
then
y=25
substitute
[tex]25=-75-5x[/tex]
Solve for the function input is the same that solve for x
Isolate the variable x
Adds 5x both sides
[tex]25+5x=-75-5x+5x[/tex]
[tex]25+5x=-75[/tex]
subtract 25 both sides
[tex]25+5x-25=-75-25[/tex]
[tex]5x=-100[/tex]
Divide by 5 both sides
[tex]x=-20[/tex]
therefore
The function input is -20 when the output is 25
