Answer:
6(3d+2)
Step-by-step explanation:
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 
Answer:
The second amount is 3.72
Step-by-step explanation:
Given


Required
Find Second

Substitute 9.92 for First

Express as fraction

Multiply both sides by 9.92



Answer:
Solve for the first variable in one of the equations, then substitute the result into the other equation.
Point Form:(30/19,2/19)
Equation Form: x=30/19, y=2/19
Answer:
-13/20
Step-by-step explanation:
-0.65=-65/100
=13/20