Answer:
<em>The speed of the plane in still air is 590 mph</em>
<em>The speed of the wind is 20 mph</em>
Step-by-step explanation:
Let's call:
x = Speed of the plane in still air
y = Speed of the wind
The plane traveled d=4575 miles with the wind in t=7.5 h. The speed calculated with this data corresponds to the sum of the speed of the plane and the speed of the wind, thus:

x + y = 610 [1]
The plane traveled 4275 miles in 7.5 hours against the wind, thus the speed calculated is x - y:

x - y = 570 [2]
Adding [1] and [2]:
2x = 610 + 570 = 1180
x = 1180 / 2 = 590
From [1]:
y = 610 - 590 = 20
The speed of the plane in still air is 590 mph
The speed of the wind is 20 mph
Answer:
6 hours
Step-by-step explanation:
75 x 6 = 450
Step-by-step explanation:
![9x^{2} - 9 (a + b)x + 2a^{2} + 5ab + 2b^{2} = 0\\9x^{2} - 3[(3a + 3b)]x + 2a^{2} + 4ab +ab + 2b^{2} = 0\\9x^{2} - 3[(a + 2b) + (2a + b)]x + 2a[a + 2b] + b [a + 2b] = 0\\9x^{2} - 3(a + 2b)x - 3 (2a + b) + (a + 2b)(2a + b) = 0\\3x [3x - (a + 2b)] -(2a + b)[3x - (a + 2b)]=0\\\:\: [3x - (a + 2b)] - [3x - (2a + b)] = 0\\\\\\\\\circ\:3x - (2a + b) = 0\\\boxed{\underline{x = \frac{2a + b}{3} }}\\\\\\\\\circ\:3x - (2a + b) = 0\\\boxed{\underline{x = \frac{a + 2b}{3} }}](https://tex.z-dn.net/?f=9x%5E%7B2%7D%20-%209%20%28a%20%2B%20b%29x%20%2B%202a%5E%7B2%7D%20%2B%205ab%20%2B%202b%5E%7B2%7D%20%3D%200%5C%5C9x%5E%7B2%7D%20-%203%5B%283a%20%2B%203b%29%5Dx%20%2B%202a%5E%7B2%7D%20%2B%204ab%20%2Bab%20%2B%202b%5E%7B2%7D%20%3D%200%5C%5C9x%5E%7B2%7D%20-%203%5B%28a%20%2B%202b%29%20%2B%20%282a%20%2B%20b%29%5Dx%20%2B%202a%5Ba%20%2B%202b%5D%20%2B%20b%20%5Ba%20%2B%202b%5D%20%3D%200%5C%5C9x%5E%7B2%7D%20-%203%28a%20%2B%202b%29x%20-%203%20%282a%20%2B%20b%29%20%20%2B%20%28a%20%2B%202b%29%282a%20%2B%20b%29%20%3D%200%5C%5C3x%20%5B3x%20-%20%28a%20%2B%202b%29%5D%20-%282a%20%2B%20b%29%5B3x%20-%20%28a%20%2B%202b%29%5D%3D0%5C%5C%5C%3A%5C%3A%20%5B3x%20-%20%28a%20%2B%202b%29%5D%20-%20%5B3x%20-%20%282a%20%2B%20b%29%5D%20%3D%200%5C%5C%5C%5C%5C%5C%5C%5C%5Ccirc%5C%3A3x%20-%20%282a%20%2B%20b%29%20%3D%200%5C%5C%5Cboxed%7B%5Cunderline%7Bx%20%3D%20%5Cfrac%7B2a%20%2B%20b%7D%7B3%7D%20%7D%7D%5C%5C%5C%5C%5C%5C%5C%5C%5Ccirc%5C%3A3x%20-%20%282a%20%2B%20b%29%20%3D%200%5C%5C%5Cboxed%7B%5Cunderline%7Bx%20%3D%20%5Cfrac%7Ba%20%2B%202b%7D%7B3%7D%20%7D%7D)
So, the roots are:
<u>1) x = 2a + b/3</u>
<u>2) x = a + 2b/3</u>
_________
Hope it helps!
◇ Please refer to the attachment if the latex code shows some error.

A) y=(-0.49)x²+23.38x+996.03
B) 1267.63
Use technology for part A.
Using the equation from part A, substitute 20 in place of x:
y=(-0.49)(20²)+23.38(20)+996.03
y=1267.63
If slope of a line is m then slope of the perpendicular line is -1/m .
so slope of perpendicular line is -3.
then use this y-y0=m(x-x0)
y+5=-3(x-2)
y+5=-3x+6
y=-3x+1