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: 5
Step-by-step explanation: Let's go over a little algebra terminology.
The number in front of your variable is called your coefficient and a variable is just a letter that represents any number.
So here, your coefficient is 5 since it appears in front of the variable, x.
Step-by-step explanation:
It is possible
One person will get 246 while the other will get 266 = 512
Answer:
Step-by-step explanation:
4x+y=14
x-2y=8
then;
x=8-2y
substitute;
4(8-2y)+8-2y=14
32-8y+8-2y=14
40-10y=14
26=10y
y=2.6 , work out 4x+2.6=14 to get x