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:
4% sales tax
Step-by-step explanation:
Take the original costs and subtract it from the price after sales tax.
$84.24-$81= $3.24
Divide 3.24 by 81
this gives you .04, now either multiply by 100 or move the decimal two places to the right to convert the decimal to a percentage.
Answer:
14
Step-by-step explanation:
rectangle 8
triangle 6
Answer:
Step-by-step explanation:
First factor the second binomial
38^9 - 38^8 = 38^9 (38 - 1 ) = 38^9(37)
So there's your 37. This whole expression is divisible by 37
Now do the first binomial
36^5 - (36^4)*6
36^4(36 - 6)
36^4(30) and there's your thirty.
That first term is going to cause a bit of trouble showing that 36^4 * 6 = 6^9
6(36^4) = 6(6^2)^4 = 6^1 * 6^8 = 6^9
So this factors into 30*(36^4)*37*38^9