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:
not really good at maths. 15.33
Step-by-step explanation:
3(x-5)-7=3×8
3x-15-7=24
3x =24+15+7
3x = 46
Three will divide it's self to give you one and divide 46 to give you 15.333
(correct me if i'm wrong)
Answer:
36/132
Step-by-step explanation:
36/132, .27, 27%...
We are given the function <span>–2x – 4 + 5x = 8 and is asked in the problem to solve for the variable x in the function. In this case, we can first group the like terms and put them in their corresponding sides:
-2x + 5x =8+4
Then, do the necessary operations.
3x = 12
x = 4.
The variable x has a value of 4.</span>