Answer: 12in
Step-by-step explanation:
Length+width+length+width
8x-9y=19
4x+y=-7
Multiply all terms of the 2nd by (9)===> 36x + 9y= 63
add (36x 9y= 63) to the 1st ===> 44x+0y = -44 ===> x=-1
replace x by this value in any of the equation & you'll get y=-3
Answer:
360 mi/h
Step-by-step explanation:
The speed for the outbound trip was ...
speed = distance/time = (715 mi)/(2 1/6 h) = 330 mi/h
The inbound speed was ...
(715 mi)/(1 5/6 h) = 390 mi/h
The airspeed of the plane is the average of these two ground speeds, so is ...
(330 +390)/2 = 360 . . . . mi/h
Divide 5 by 89 and you get a=17.8
