Question 881193
At {{{t=0}}}, {{{V=7500}}}.
At {{{t=5}}}, {{{V=4500}}}.
Find the slope, {{{(DELTA*V)/(DELTA*t)=(4500-7500)/(5-0)=-3000/5=-600}}}
Then use the point slope form of a line,
{{{V-7500=-600(t-0)}}}
{{{V=7500-600t}}}