Answer:
B. 41.8° is the correct answer
Step-by-step explanation:
We are given that,
Length of Eduardo's flight path = 273 miles
Length of Paul's flight path = 357 miles
Distance between their destinations = 238 miles.
Now, using the law of cosines, we get,
i.e. 
i.e. 
i.e. 
i.e. 
i.e. 
i.e. θ = 41.8°
Hence, the angle between their flight paths is 41.8°.
Angle QRT is an exterior angle to the triangle. The rule is that the exterior angle of a triangle is equal to the sum of its remote interior angles. Those remote interior angles are angle RTS and angle TSR. So our equation is
. We can remove the parenthesis and simplify by combining like terms to get 9x = 5x + 9 + x and 9x = 6x + 9 and 3x = 9. That means that x = 3.
<span>x^2 + 15x + 56.25 = 105.25
"Completing the square" is one of many different techniques for solving a quadratic equation. What you do is add a constant to both sides of the equation such that the lefthand side can be factored into the form a(x+d)^2. For instance, squaring (X+D) = X^2 + 2DX + D^2. Notice the 2DX term. That is the same term as the 15x term in the problem. So 2D = 15, D = 7.5. And D^2 = 7.5^2 = 56.25.
So we have
x^2 + 15x + 56.25 = 49 + 56.25
Which is
x^2 + 15x + 56.25 = 105.25
Which is the answer desired.
Now the rest of this is going beyond the answer. Namely, it's answering the question "Why does complementing the square help?"
Well, we know that the left hand side of the equation can now be written as
(x+7.5)^2 = 105.25
Now take the square root of each side
(x+7.5) = sqrt(105.25)
And let's use both the positive and negative square roots.
So
x+7.5 = 10.25914226
and
x+7.5 = -10.25914226
And let's find X.
x+7.5 = 10.25914226
x = 2.759142264
x+7.5 = -10.25914226
x = -17.75914226
So the roots for x^2 + 15x - 49 is 2.759142264, and -17.75914226</span>
X/4 + 12 = 5
to isolate the variable the first step is to subtract 12 from both sides
x/4 + 12 - 12 = 5 - 12
x/4 = -7
next, to get rid of the division by 4, multiply both sides by 4
(x/4)*4 = -7*4
x = -28
Since complementary angles add up to 90 degrees, we simple take
and simplify it to
°
