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3 years ago

11

Evaluate the following expression given that z=8 2z-4

1 answer:

PtichkaEL [24]3 years ago

5 0

Answer:

12

Step-by-step explanation:

2 times 8 is 16. 16 minus 4 is 12.

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What is the balance after one year on an investment of $20,000 earning 5.2% interest compounded annually? what is the answer

Stells [14]

Answer:

1040

Step-by-step explanation:

20,000 is how much you have and you would multiply 20,000*5.2% or 20,000*.052 (converting a percent to a decimal.)

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3 years ago

X^2/ 2x^2 -4 * x ^2 / x+3<br> 30 points fraction cross multiply question

andrew11 [14]

Answer:

nmnsggx

Step-by-step explanation:

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3 years ago

Find the point (,) on the curve =8 that is closest to the point (3,0). [To do this, first find the distance function between (,)

ELEN [110]

Question:

Find the point (,) on the curve $y = \sqrt x$ that is closest to the point (3,0).

[To do this, first find the distance function between (,) and (3,0) and minimize it.]

Answer:

$(x,y) = (\frac{5}{2},\frac{\sqrt{10}}{2}})$

Step-by-step explanation:

$y = \sqrt x$ can be represented as: $(x,y)$

Substitute $\sqrt x$ for $y$

$(x,y) = (x,\sqrt x)$

So, next:

Calculate the distance between $(x,\sqrt x)$ and $(3,0)$

Distance is calculated as:

$d = \sqrt{(x_1-x_2)^2 + (y_1 - y_2)^2}$

So:

$d = \sqrt{(x-3)^2 + (\sqrt x - 0)^2}$

$d = \sqrt{(x-3)^2 + (\sqrt x)^2}$

Evaluate all exponents

$d = \sqrt{x^2 - 6x +9 + x}$

Rewrite as:

$d = \sqrt{x^2 + x- 6x +9 }$

$d = \sqrt{x^2 - 5x +9 }$

Differentiate using chain rule:

Let

$u = x^2 - 5x +9$

$\frac{du}{dx} = 2x - 5$

So:

$d = \sqrt u$

$d = u^\frac{1}{2}$

$\frac{dd}{du} = \frac{1}{2}u^{-\frac{1}{2}}$

Chain Rule:

$d' = \frac{du}{dx} * \frac{dd}{du}$

$d' = (2x-5) * \frac{1}{2}u^{-\frac{1}{2}}$

$d' = (2x - 5) * \frac{1}{2u^{\frac{1}{2}}}$

$d' = \frac{2x - 5}{2\sqrt u}$

Substitute: $u = x^2 - 5x +9$

$d' = \frac{2x - 5}{2\sqrt{x^2 - 5x + 9}}$

Next, is to minimize (by equating d' to 0)

$\frac{2x - 5}{2\sqrt{x^2 - 5x + 9}} = 0$

Cross Multiply

$2x - 5 = 0$

Solve for x

$2x =5$

$x = \frac{5}{2}$

Substitute $x = \frac{5}{2}$ in $y = \sqrt x$

$y = \sqrt{\frac{5}{2}}$

Split

$y = \frac{\sqrt 5}{\sqrt 2}$

Rationalize

$y = \frac{\sqrt 5}{\sqrt 2} * \frac{\sqrt 2}{\sqrt 2}$

$y = \frac{\sqrt {10}}{\sqrt 4}$

$y = \frac{\sqrt {10}}{2}$

Hence:

$(x,y) = (\frac{5}{2},\frac{\sqrt{10}}{2}})$

3 0

3 years ago

Determine the equation of the line that goes through points (1.1) and (3.7).

ValentinkaMS [17]

Answer:

The equation of the line that goes through points (1,1) and (3,7) is $\mathbf{y=3x-2}$

Step-by-step explanation:

Determine the equation of the line that goes through points (1,1) and (3,7)

We can write the equation of line in slope-intercept form $y=mx+b$ where m is slope and b is y-intercept.

We need to find slope and y-intercept.

Finding Slope

Slope can be found using formula: $Slope=\frac{y_2-y_1}{x_2-x_1}$

We have $x_1=1, y_1=1, x_2=3, y_2=7$

Putting values and finding slope

$Slope=\frac{y_2-y_1}{x_2-x_1}\\Slope=\frac{7-1}{3-1}\\Slope=\frac{6}{2}\\Slope=3$

We get Slope = 3

Finding y-intercept

y-intercept can be found using point (1,1) and slope m = 3

$y=mx+b\\1=3(1)+b\\1=3+b\\b=1-3\\b=-2$

We get y-intercept b = -2

So, equation of line having slope m=3 and y-intercept b = -2 is:

$y=mx+b\\y=3x-2$

The equation of the line that goes through points (1,1) and (3,7) is $\mathbf{y=3x-2}$

4 0

3 years ago

How many solutions do you think the equation -10x+3=5x-27 has? Explain. Then, find the solution(s).

deff fn [24]

This will only have one solution because it does not deal with a quadratic. Then to isolate x you need to get the similar terms on different sides by subtracting or adding, Then divide both sides by the number next to x (coefficient).

4 0

3 years ago