Question

Please help me right away.

Answer 1

we are given

$x(t)=700-30t-15t^2$

Average rate of change:

we can use formula

$v(t)=\frac{x(t)-x(0)}{t-0}$

$x(t)=700-30t-15t^2$

$x(0)=700-30(0)-15(0)^2$

$x(0)=700$

now, we can plug value

and we get

$v(t)=\frac{700-30t-15t^2-700}{t-0}$

now, we can simplify it

$v(t)=\frac{-30t-15t^2}{t}$

$v(t)=\frac{t(-30-15t)}{t}$

now, we can cancel t

$v(t)=-30-15t$

so, option-d.............Answer