Answer: see proof below
<u>Step-by-step explanation:</u>
Use the Sum & Difference Identity: cos (A + B) = cos A · cos B - sin A · sin B
Recall the following from Unit Circle: cos (π/2) = 0, sin (π/2) = 1
cos (π) = -1, sin (π) = 0
Use the Quotient Identity: 
<u>Proof LHS → RHS:</u>




Quotient: tan x
LHS = RHS 
So here is how we are going to find the answer. Firstly, we deduct 58 from 76 and we got 18. The decrease is $18. Now, we are going to find out how many percent is 18 of 76. So we divide 18 by 76 multiplied by 100 and we get 23.7%. Hope this answers your question. Have a great day!
1. Cross multiply
35x = 5(11)
35x = 55
Divide both sides by 35
x = 55/35
x = 11/7
2. (x - 2)/x = 3/8
Cross multiply
3x = 8(x - 2)
3x = 8x - 16
Subtract 8x from both sides
-5x = -16
divide both sides by -5
x = -16/-5
x = 16/5 OR 3 1/5
3. (a + 1)/(a - 1) = 5/6
cross multiply
6(a + 1) = 5(a - 1)
distribute
6a + 6 = 5a - 5
subtract 5a from both sides
a + 6 = -5
subtract 6 from both sides
a = -11
4. (1/3)x - 4 = (2/3)x + 6
multiply each term by 3 to clear the fractions
x - 12 = 2x + 18
subtract x from both sides
-12 = x + 18
subtract 18 from both sides
-30 = x
86 years old because you subtract 2017-1931
Answer:
False i just did it
Step-by-step explanation: