You multiply both sides by 9 first so you have -45=y-7. then add 7 to both sides to get y=-38
That number is the ratio of 578,778,777 to 100,000,000 , so it's rational.
Here's a surprising factoid:
ANY number that you can completely write down on paper with digits...
and a decimal point or a fraction bar if you need them ... is rational.
If you can write it down ... without saying "repeating" or using symbols ...
it's rational.
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:
20400
Step-by-step explanation:
its 2.03x10x10x10x10 so first ten: 20.4 and ten: 204 3rd ten: 2040 last ten :20400
Answer:
8.5 inches
Step-by-step explanation:
1/2 in = 5 miles
? = 85 miles.
So you would do 85/5 to figure out how many times you have to multiply 5 to get to 85.
85/5= 17
So then you would multiply 17 by 1/2 to get the answer 8.5. So that would b 8.5 inches