Aplane can travel 480 miles per hour with the wind and 440 miles per hour against the wind find the speed of the wind and the speed of the plane in still air

Wind speed = x

planes speed with wind: 480-x
planes speed against wind: 440+x
 set them to equal and solve for x ( wind speed)

480-x = 440 +x

add x to each side:

480 = 440 +2x ( x+x=2x)

480 = 440 +2x
 subtract 440 from each side:

40 = 2x

divide both sides by 2
x = 40/2
x = 20 

wind speed = 20 miles per hour

speed of plane in still air = 480-20 = 460 miles per hour

(m+11n)^2=(m+11n)(m+11n)=m^2+11mn+11mn+121n^2=m^2+22mn×121n^2 for example; use foil: (a+b)(a+b)first. a^2outside. abinside. ablast. b^2