Question 269101
D=RT OR T=D/R
T=200/(R-30)
T=300/(R+30)
THE 2 TIMES ARE EQUAL THUS THE EQUATIONS ARE EQUAL
200/(R-30)=300/(R+30) CROSS MULTIPLY
300(R-30)=200(R+30)
300R-9000=200R+6000
300R-200R=6000+9000
100R=15000
R=15000/100
R=150 MPH IS THE SPEED OF THE PLANE IN STILL AIR.
PROOF:
200/(150-30)=300/(15+30)
200/120=300/180
5/3=5/3