-4y = 8x
Divide both sides by -4
y = -2x
This is in the form of y = kx, where k is the constant of variation.
y = kx is the direct
That means, k = -2.
The constant of variation is B. -2.
Answer:
The slope of y=-3x+2 is B. -3
As soon as I read this, the words "law of cosines" popped
into my head. I don't have a good intuitive feeling for the
law of cosines, but I went and looked it up (you probably
could have done that), and I found that it's exactly what
you need for this problem.
The "law of cosines" relates the lengths of the sides of any
triangle to the cosine of one of its angles ... just what we need,
since we know all the sides, and we want to find one of the angles.
To find angle-B, the law of cosines says
b² = a² + c² - 2 a c cosine(B)
B = angle-B
b = the side opposite angle-B = 1.4
a, c = the other 2 sides = 1 and 1.9
(1.4)² = (1)² + (1.9)² - (2 x 1 x 1.9) cos(B)
1.96 = (1) + (3.61) - (3.8) cos(B)
Add 3.8 cos(B) from each side:
1.96 + 3.8 cos(B) = 4.61
Subtract 1.96 from each side:
3.8 cos(B) = 2.65
Divide each side by 3.8 :
cos(B) = 0.69737 (rounded)
Whipping out the
trusty calculator:
B = the angle whose cosine is 0.69737
= 45.784° .
Now, for the first time, I'll take a deep breath, then hold it
while I look back at the question and see whether this is
anywhere near one of the choices ...
By gosh ! Choice 'B' is 45.8° ! yay !
I'll bet that's it !
Answer:
60 kilometers per hour.
420 kilometers will be covered
Step-by-step explanation:
speed = distance ÷ time.
so 60kmh = 240km divided by 4 Hours
60km = 1 Hour of distance
240km = 4 Hours of distance
Therefore 60 x 3 hour is 180km added to 240 is 420km. So in 7 hours traveling 60 kilometers per hour the will cover 420kms.
