Answer:P=2x + 2y + 8
Step-by-step explanation: Perimeter (p) =2L+ 2w
P= 2(x+5)+2(y-1)
Remove bracket
P=2x+ 10 +2y - 2
P=2x+2y+8
Answer:
x=65/n where x is 1 book and n the number of books
Step-by-step explanation:
If n is the number of books, lets say 1 book is "x", then
nx=65
x=65/n
for example
n=1 then x=65
n=2 then x=65/2
n=3 then x=65/3
Answer: 30 ft
Step-by-step explanation:
Cross multiply:
6 : 3.5
x : 17.5
Then divide 105 with 3.5x.
105/3.5x = 30
Answer: The amount of salt in the tank after 8 minutes is 36.52 pounds.
Step-by-step explanation:
Salt in the tank is modelled by the Principle of Mass Conservation, which states:
(Salt mass rate per unit time to the tank) - (Salt mass per unit time from the tank) = (Salt accumulation rate of the tank)
Flow is measured as the product of salt concentration and flow. A well stirred mixture means that salt concentrations within tank and in the output mass flow are the same. Inflow salt concentration remains constant. Hence:

By expanding the previous equation:

The tank capacity and capacity rate of change given in gallons and gallons per minute are, respectivelly:

Since there is no accumulation within the tank, expression is simplified to this:

By rearranging the expression, it is noticed the presence of a First-Order Non-Homogeneous Linear Ordinary Differential Equation:
, where
.

The solution of this equation is:

The salt concentration after 8 minutes is:

The instantaneous amount of salt in the tank is:
Equation of a line passing through point (x1, y1) with slope m is given by y - y1 = m(x - x1)
For parallel lines, the slope of the required line is equal to the slope of the given line.
x = -3 is a vertical line, therefore, the required line will also be a vertical line since they are parallel.
Since the required line passes through point (4, 2), the equation of the required line is x = 4.