Answer: see proof below
<u>Step-by-step explanation:</u>
Given: A + B + C = π and cos A = cos B · cos C
scratchwork:
A + B + C = π
A = π - (B + C)
cos A = cos [π - (B + C)] Apply cos
= - cos (B + C) Simplify
= -(cos B · cos C - sin B · sin C) Sum Identity
= sin B · sin C - cos B · cos C Simplify
cos B · cos C = sin B · sin C - cos B · cos C Substitution
2cos B · cos C = sin B · sin C Addition
Division
2 = tan B · tan C
<u>Proof LHS → RHS</u>
Given: A + B + C = π
Subtraction: A = π - (B + C)
Apply tan: tan A = tan(π - (B + C))
Simplify: = - tan (B + C)
Substitution: = -(tan B + tan C)/(1 - 2)
Simplify: = -(tan B + tan C)/-1
= tan B + tan C
LHS = RHS: tan B + tan C = tan B + tan C 
Sin(θ - 180)
sin(θ)cos(180) - cos(θ)sin(180)
sin(θ)[-1] - cos(θ)[0]
-sin(θ) - 0
-sin(θ)
Answer:
1) 6x = 21
2) x + y - 3
3) x/z = y
4) 2-x = p
Step-by-step explanation:
1. The product of a number x and 6 is 21
A product is a multiplication. A product of a and b is a * b.
We then have a product of x and 6, that x * 6, which we write usually in the format 6x.
is 21: that means it's equal to 21....
so 6x = 21.
2. The sum of the quantity x- 3 and y
The sum is an addition. The sum of a and b is a + b.
In this case, the first part is x - 3, the second part is y
So, x - 3 + y, which we usually rewrite as x + y - 3
3. The quotient of x and z is y
A quotient is a division.
So, quotient of x and z is x/z.
x/z = y
4. The difference of 2 and x is p.
A difference is a subtraction.
Difference of 2 and x is 2 - x
2 - x = p
Answer:
D. 12m-15
Step-by-step explanation:
3(4m-5)=3*4m-3*5=12m-15
Answer:
oof
Step-by-step explanation:
