therfor

X+Y=645 and

X-Y=575

therfore if we use simultanius equationswe can work out that 2X=645+575

2X=1220

X=610

if we substitute this into the first equation we get Y =35

therfore X=610 and Y=35

I think!

645+575=1220

1220/2= 610

610 is the speed of the plane in still air.

the difference between 610 and 645 = 35 mph is the speed of the wind

(can also do difference of 610 and 575 = 35 mph) you will get a positive and a negative 35 depending on which way you do it, that just means the wind is blowing at you in one direction and away from you on the other.

In short, not enough info, but I’d guess 35 MPH, with the plane going 610 in still air.