1/3 times what equals -1

Write the equation of the line that passes through each pair of points in slope-intercept form. This is worth 3 points. You have

LekaFEV [45]

(0,5)(3,-1)
slope = (-1 - 5) / (3 - 0) = -6/3 = -2

y = mx + b
slope(m) = -2
(use either of ur points...(0,5)...x = 0 and y = 5
now we sub and find b, the y int
5 = -2(0) + b
5 = b

so ur line is : y = -2x + 5

6 0

2 years ago

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Bob's mom is 3 times older than Bob. In 12 years, Bob's mom's age will be twice of

shusha [124]

I would use a chart to solve this problem.

This is a good wya to organize your information.

Down the left side, list the people involved.

I put Bob first and the mom second but the order doesn't matter.

Since Bob's mom is 3 times older than Bob, we can represent

Bob's age now as x and Bob's mom's age now as 3x.

Bob's age in 12 years will be x + 12 and Bob's mom's

age in 12 years will simply be 3x + 12.

Since the second sentence starts with in 12 years,

we will be using the information from our second column.

In 12 years, Bob's mom's age, 3x + 12, will be,

equals, twice of her son's age, 2(x + 12).

Solving from here, we find that x = 12.

This means that Bob's age now is 12 and his mom is 36.

The chart is attached below.

6 0

2 years ago

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Find the slope of the line that passes through (6, 4) and (4, 5).

Vikki [24]

The answer is m=-1/2

4 0

3 years ago

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A 500-gallon tank initially contains 220 gallons of pure distilled water. Brine containing 5 pounds of salt per gallon flows int

Wittaler [7]

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:

$c_{0} \cdot f_{in} - c(t) \cdot f_{out} = \frac{d(V_{tank}(t) \cdot c(t))}{dt}$

By expanding the previous equation:

$c_{0} \cdot f_{in} - c(t) \cdot f_{out} = V_{tank}(t) \cdot \frac{dc(t)}{dt} + \frac{dV_{tank}(t)}{dt} \cdot c(t)$

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

$V_{tank} = 220\\\frac{dV_{tank}(t)}{dt} = 0$

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

$c_{0} \cdot f_{in} - c(t) \cdot f_{out} = V_{tank}(t) \cdot \frac{dc(t)}{dt}$

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

$V_{tank} \cdot \frac{dc(t)}{dt} + f_{out} \cdot c(t) = c_0 \cdot f_{in}$ , where $c(0) = 0 \frac{pounds}{gallon}$ .

$\frac{dc(t)}{dt} + \frac{f_{out}}{V_{tank}} \cdot c(t) = \frac{c_0}{V_{tank}} \cdot f_{in}$

The solution of this equation is:

$c(t) = \frac{c_{0}}{f_{out}} \cdot ({1-e^{-\frac{f_{out}}{V_{tank}}\cdot t }})$

The salt concentration after 8 minutes is:

$c(8) = 0.166 \frac{pounds}{gallon}$

The instantaneous amount of salt in the tank is:

$m_{salt} = (0.166 \frac{pounds}{gallon}) \cdot (220 gallons)\\m_{salt} = 36.52 pounds$

3 0

3 years ago

The length and breadth of a rectangular field are 312m and 186m respectively; correct to the nearest metres. Between what limits

lisabon 2012 [21]

Answer:

$P \geq 1000 \; meters$

Step-by-step explanation:

<u>Given the following data;</u>

Length = 312 meters

Breadth = 186 meters

To find the perimeter of the rectangle;

Mathematically, the perimeter of a rectangle is given by the formula;

Perimeter = 2(L + W)

Perimeter = 2(312 + 186)

Perimeter = 2(498)

Perimeter = 996 meters

To the nearest meters, we have;

Perimeter = 996 ≈ 1000 meters

Let P represent the perimeter of a rectangular field.

900 < P > 1000

Therefore, $P \geq 1000 \; meters$

8 0

2 years ago