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:
2(3x+4) = 11x-17
6x+8 = 11x-17
25=-5x
x=-5
11x-17
55-17
38
AC = 38
CD = 38
49-38 = 11
DE = 11
Let me know if this helps!
try this for answer (11×3.5)-9=x
Answer:
13
Step-by-step explanation:
this would be 13
Answer:
7 is the answer
Step-by-step explanation:
2x7=14