Question 309870
Think of 1 plane as stationary and the other as moving away from it
at the sum of their speeds
Let {{{s}}} = the speed of the faster plane
{{{s - 25}}} = the speed of the slower plane
The sum of their speeds is {{{s + s - 25 = 2s - 25}}}
In 2 hrs:
{{{470 = (2s - 25)*2}}}
{{{470 = 4s - 50}}}
{{{4s = 520}}}
{{{s = 130}}}
{{{s - 25 = 105}}}
The 1st planes flies at 105 mi/hr
The 2nd plane flies at 130 mi/hr
check:
1st plane:
{{{d[1] = 105*2}}}
{{{d[1] = 210}}} mi
2nd plane:
{{{d[2] = 130*2}}}
{{{d[2] = 260}}}
{{{d[1] + d[2] = 210 + 260}}}
{{{d[1] + d[2] = 470}}}
OK