Answer:

Step-by-step explanation:
when adding logs, apply the log rule: 
∴ 
when subtracting logs, apply the log rule: 

Answer:
Cost, C = $28410.72
Step-by-step explanation:
We have, a concrete pillar has the shape of a cylinder.
Diameter of pillar is 8 m and ts height is 9 m
If concrete costs $87 per cubic meter, it is required to find the concrete cost for the pillar. For this lets find the area of cylindrical shape. So,

The cost of pillar at the rate of $87 per cubic meter will be :

(trying to isolate/get x by itself in the equation)
5(x + 6) = 50 Distributive property [distribute 5 into (x + 6)]
5x + 30 = 50 Subtraction [subtract 30 on both sides of the equation]
5x = 20 Division [divide 5 on both sides]
x = 4
Subtraction then division, the 2nd option
Answer:
y = -2x + 16.
Step-by-step explanation:
The slope of the perpendicular line = -1 / slope of the given line
= -1 / 1/2 = -2.
Using the point slope form of the equation of a straight line:
y - y1 = m (x - x1)
y - 8 = -2(x - 4)
y - 8 = -2x + 8
y = -2x + 16 is the required equation.