Question 921359
RT=D rate time distance, basic rule for uniform rates of travel.


_____________rate__________time_________distance
PLANE_________r_____________t____________{{{300=rt}}}
CAR_________r-90____________t____________{{{120=(r-90)t}}}


This data table is filled to show two equations in the two unknowns, r and t, using RATE*TIME=DISTANCE.  You need to perform the necessary algebraic steps to solve for r and t.  You may need to use two substitutions, and you may find a quadratic equation resulting in the process.


Okay, I saw your latest message; but TRY solving the system.  The process is simpler than I thought.  No need for any quadratic in the process.



Do that solving properly and you should find  {{{t=2}}};
{{{r=150}}}; 
and {{{r-90=60}}}.