This is the last thing i have to do for the rest of the week im begging you guys to help me

Consider the function f(x)=-5x+3 what is f(-2)

(60 points) explain this in detail

The value, v, of kalani’s stock investments over a time period, x, can be determined using the equation v=750(0.80)^-x. what is the rate of increase or decrease associated with this account? 20% decrease 20% increase 25% decrease 25% increase