3/10 2/7 1/4 3/5 that is least to greatest
Answer:
Step-by-step explanation:
We are to show that 
<u>Proof:</u>
From trigonometry identity;


From trigonometry, 2sinAcosA = Sin2A

Also note that sin(B-C) = sinBcosC - cosBsinC
sin420cos140 - cos420sin140 = sin(420-140)
The resulting equation becomes;

= 
Answer:
B) 42:28
Step-by-step explanation:
First, let's get 12:18 simplified to make it easier to compare:
12:18 -> 4:6 - > <u>2:3</u>
Now let's check it against all the options:
A) 20:30 -> 2:3 and 2:3 = 2:3
Not our answer as it is congruent (equal too, the same as, etc)
B) We can see that the first number is larger than the second number, so without doing too much math we can see this is our answer!
42:28
(it simplifes to 6:4 -> 3:2)
(we do not have to do the following as we already have an answer, but here is the math)
C) 4:6
4:6 ->
2:3 = 2:3
D) 2:3
2:3 = 2:3