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4 years ago

I really need some help so please help me!!!

Mathematics

1 answer:

Margarita [4]4 years ago

4 0

(0,3) the cost per mile traveled

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Show work please<br> \sqrt(x+12)-\sqrt(2x+1)=1

Nesterboy [21]

Answer:

$x=4$

Step-by-step explanation:

Given $\displaystyle\\\sqrt{x+12}-\sqrt{2x+1}=1$ , start by squaring both sides to work towards isolating $x$ :

$\displaystyle\\\left(\sqrt{x+12}-\sqrt{2x+1}\right)^2=\left(1\right)^2$

Recall $(a-b)^2=a^2-2ab+b^2$ and $\sqrt{a}\cdot \sqrt{b}=\sqrt{a\cdot b}$ :

$\displaystyle\\\left(\sqrt{x+12}-\sqrt{2x+1}\right)^2=\left(1\right)^2\\\implies x+12-2\sqrt{(x+12)(2x+1)}+2x+1=1$

Isolate the radical:

$\displaystyle\\x+12-2\sqrt{(x+12)(2x+1)}+2x+1=1\\\implies -2\sqrt{(x+12)(2x+1)}=-3x-12\\\implies \sqrt{(x+12)(2x+1)}=\frac{-3x-12}{-2}$

Square both sides:

$\displaystyle\\(x+12)(2x+1)=\left(\frac{-3x-12}{-2}\right)^2$

Expand using FOIL and $(a+b)^2=a^2+2ab+b^2$ :

$\displaystyle\\2x^2+25x+12=\frac{9}{4}x^2+18x+36$

Move everything to one side to get a quadratic:

$\displaystyle-\frac{1}{4}x^2+7x-24=0$

Solving using the quadratic formula:

A quadratic in $ax^2+bx+c$ has real solutions $\displaystyle x=\frac{-b\pm \sqrt{b^2-4ac}}{2a}$ . In $\displaystyle-\frac{1}{4}x^2+7x-24$ , assign values:

$\displaystyle \\a=-\frac{1}{4}\\b=7\\c=-24$

Solving yields:

$\displaystyle\\x=\frac{-7\pm \sqrt{7^2-4\left(-\frac{1}{4}\right)\left(-24\right)}}{2\left(-\frac{1}{4}\right)}\\\\x=\frac{-7\pm \sqrt{25}}{-\frac{1}{2}}\\\\\begin{cases}x=\frac{-7+5}{-0.5}=\frac{-2}{-0.5}=\boxed{4}\\x=\frac{-7-5}{-0.5}=\frac{-12}{-0.5}=24 \:(\text{Extraneous})\end{cases}$

Only $x=4$ works when plugged in the original equation. Therefore, $x=24$ is extraneous and the only solution is $\boxed{x=4}$

4 0

2 years ago

What’s the answer plz!!

Karolina [17]

I think its the secondd

8 0

4 years ago

Read 2 more answers

Write an equation that represents the pattern in the table

Slav-nsk [51]

Y=3x

explain
4x3=12 , 5x3=15 , 6x3=18 ,.......

8 0

3 years ago

help me find the volume and area of this figure step by step pleasefyi the answer key my teacher gave me says that the surface a

alisha [4.7K]

The volume of the shape

We have a cylinder that is cut into two. Its external radius is 5ft, while its internal radius is 4ft.

External radius = internal radius + thickness

$\begin{gathered} \text{External radius = 4ft + 1ft } \\ =\text{ 5ft} \end{gathered}$

Internal radius = 4ft (given)

Recall that the volume(V) of a full cylinder is:

$V\text{ = }\pi r^2h$

Since the cylinder is cut into two, the volume(V) is:

$V\text{ = }\frac{\pi r^2h}{2}$

height (h) = 12ft (given)

The volume of the shape:

$\begin{gathered} =\text{ Volume of cylinder with a radius of 5ft - Volume of cylinder with a radius of 4ft} \\ =\text{ }\frac{\pi\text{ }\times5^2\text{ }\times\text{ 12}}{2}\text{ - }\frac{\pi\text{ }\times4^2\text{ }\times\text{ 12}}{2} \\ =\text{ 471.239 - }301.593 \\ =169.65ft^3 \end{gathered}$

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1 year ago

If synthetic division reveals a zero, why should we try that value again as a possible solution?

9966 [12]

Polynomials can have double roots, in fact they're pretty common. if you get a reasonable zero it costs very little time to try it again for a double root. answer is the second choice

6 0

3 years ago

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