Answer:
[tex]y=-30x+210[/tex]
Step-by-step explanation:
Let
x -----> the number of days
y ----> the number of minutes Yuson has left
we know that
The linear equation in slope intercept form is equal to
[tex]y=mx+b[/tex]
where
m is the slope
b is the y-coordinate of the y-intercept (initial value)
In this problem we have
The slope is equal to
[tex]m=-30\frac{min}{day}[/tex] ----> is negative because is a decreasing function
[tex]b=210\ min[/tex] ----> initial value
substitute the values
[tex]y=-30x+210[/tex]
