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3 years ago

I’m not sure how to solve this.

Mathematics

2 answers:

Elina [12.6K]3 years ago

8 0

Answer:

you use this equation because it is greater than 2

f(8)=1/2(8)+5

f(8)=4+5

f(8)=9

I hope this is good enough:

34kurt3 years ago

6 0

Answer:

f(8) = 9

Step-by-step explanation:

You would use the equation given on the bottom.

Plug in 8

f(8) = (1/2)(8) + 5 = 9

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Two trains begin in Milford and end in Pinkerton, which is 300 miles away. Train A leaves Milford at 10:00 a.M. And travels at a

cluponka [151]

Answer:

B. Train B

Step-by-step explanation:

We are told that Milford and Pinkerton is 300 miles away.

Train A leaves Milford at 10:00 am. There are 3 hours between 10:00 am to 1:00 pm. So let us find distance traveled by train A in 3 hours.

$\text{Distance}=\text{Speed*Time}$

$\text{Distance traveled by train A}=90\frac{\text{ miles}}{\text{ hour}}\times 3\text{ hours}$

$\text{Distance traveled by train A}=90\times 3{\text{ miles}$

$\text{Distance traveled by train A}=270{\text{ miles}$

Since train A will cover 270 miles in 3 hours and distance between Milford and Pinkerton is 300 miles, therefore, train A will not arrive Pinkerton before 1:00 pm.

Since there are 5 hours between 8:00 am to 1:00 pm, so let us find distance traveled by train B in 5 hours.

$\text{Distance traveled by train B}=70\frac{\text{ miles}}{\text{ hour}}\times 5\text{ hours}$

$\text{Distance traveled by train B}=70\times 5 \text{ miles}$

$\text{Distance traveled by train B}=350\text{ miles}$

Since train B will cover 350 miles in 5 hours, therefore, train B will arrive Pinkerton before 1:00 pm and option B is the correct choice.

5 0

4 years ago

Not sure what to do here can someone please help

kumpel [21]

Answer:

x = 2

Step-by-step explanation:

These equations are solved easily using a graphing calculator. The attachment shows the one solution is x=2.

<h3>Squaring</h3>

The usual way to solve these algebraically is to isolate radicals and square the equation until the radicals go away. Then solve the resulting polynomial. Here, that results in a quadratic with two solutions. One of those is extraneous, as is often the case when this solution method is used.

$\sqrt{x+2}+1=\sqrt{3x+3}\qquad\text{given}\\\\(x+2)+2\sqrt{x+2}+1=3x+3\qquad\text{square both sides}\\\\2\sqrt{x+2}=(3x+3)-(x+3)=2x\qquad\text{isolate the root term}\\\\x+2=x^2\qquad\text{divide by 2, square both sides}\\\\x^2-x-2=0\qquad\text{write in standard form}\\\\(x-2)(x+1)=0\qquad\text{factor}$

The solutions to this equation are the values of x that make the factors zero: x=2 and x=-1. When we check these in the original equation, we find that x=-1 does not work. It is an extraneous solution.

x = -1: √(-1+2) +1 = √(3(-1)+3) ⇒ 1+1 = 0 . . . . not true

x = 2: √(2+2) +1 = √(3(2) +3) ⇒ 2 +1 = 3 . . . . true . . . x = 2 is the solution

<h3>Substitution</h3>

Another way to solve this is using substitution for one of the radicals. We choose ...

$u=\sqrt{x+2}\qquad\text{requires $u\ge0$}\\\\u^2-2=x\qquad\text{solve for x}\\\\u+1=\sqrt{3(u^2-2)+3}\qquad\text{substitute for x in the original equation}\\\\(u+1)^2=3u^2-3\qquad\text{square both sides, simplify a little}\\\\2u^2-2u-4=0\qquad\text{subtract $(u+1)^2$}\\\\2(u-2)(u+1)=0\qquad\text{factor}$

Solutions to this equation are ...

u = 2, u = -1 . . . . . . the above restriction on u mean u=-1 is not a solution

The value of x is ...

x = u² -2 = 2² -2

x = 2 . . . . the solution to the equation

_____

Additional comment

Using substitution may be a little more work, as you have to solve for x in terms of the substituted variable. It still requires two squarings: one to find the value of x in terms of u, and another to eliminate the remaining radical. The advantage seems to be that the extraneous solution is made more obvious by the restriction on the value of u.

6 0

2 years ago

Find the answer given below

Anastasy [175]

Answer:

Surface area = 6l^2

Volume = l^3

If total surface area increased by 2, then the length increased by $\sqrt{2}$

Volume then is increased by ( $\sqrt{2}$ l)^3 = 2 $\sqrt{2}$ l^3

1 :2 $\sqrt{2}$

Which is not an option in the question so this question clearly has a problem.

First of all It's supposed to be "then" not "than," so I'm not sure who teaches math without even knowing this basic grammar.

Second of all, if the answer is 8:1 the question should be "If each sides of a cube is doubled" not "the lateral surface area." Come to think of it what even is lateral surface area of a cube if all sides of the cube is supposed to be same.

Or, if the answer is 2:1 then, it should be If height lateral surface area of a cube is doubled by doubling the height and without changing the length and width" But, then the the shape would no longer be a cube.

Who even wrote this garbage question what.

6 0

3 years ago

Solve for TV and SV. Select BOTH correct answers.

Papessa [141]

Answer:

Step-by-step explanation:

This is a special right triangle so the side lengths are specially measured as well

The sides that see the angle with measure 45 is represented with x

and

The side that sees the angle with measure 90 is represented with x $\sqrt{2}$

As seen, the length of TS is = 6 so is the length of TV, because this is an isosceles triangle

if x = 6 then the length of SV = 6 $\sqrt{2}$

6 0

2 years ago

The answer to this equation on my homework that my teacher gave me this morning

nasty-shy [4]

1.(40)(2.25)=90
The answer is C.90 pages.

2.(0.4)(4.2)=1.68
The answer is A.1.68 gallons

5 0

3 years ago

Read 2 more answers