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4 years ago

Solve the proportions using cross products. Round to the nearest hundredth is necessary. 21miles/49hours = 15miles h hours

1 answer:

8 0

$\dfrac{21}{49}=\dfrac{21:7}{49:7}=\dfrac{3}{7}\\\\\dfrac{21}{49}=\dfrac{15}{h}\to\dfrac{3}{7}=\dfrac{15}{h}\qquad\text{cross multiply}\\\\3h=(7)(15)\\\\3h=105\qquad\text{divide both sides by 3}\\\\\boxed{h=35}\\\\Answer:\ 35\ hours$

You might be interested in

Identify the number of solutions. Y< -1/3x+5, y> -1/3x-1.

Elenna [48]

Answer: C. No solution. ( top shaded. Middle not. Bottom shaded.

Step-by-step explanation:

Given inequalities

y< -1/3x+5 and

y> -1/3x-1.

If we draw graph for y< -1/3x+5 equation, it would be a dotted line and we would shade down the dotted line because we have less than < symbol there.

Now, if we draw graph for second inequality y> -1/3x-1, it would also be a dotted line and we would shade up of dotted line because we have greater than > symbol there.

Now, we can see that slopes of both dotted lines are same that is -1/3.

So, there would not be any common shaded region.

Therefore, there would not by any solution of the system of inequalities.

And correct option is C option.

C. No solution. ( top shaded. Middle not. Bottom shaded.

8 0

3 years ago

The hypotenuse of a right triangle measures 18 cm and one of its legs measures 12 cm. Find the measure of the other leg. If nece

Serggg [28]

Answer:

16 cm

Step-by-step explanation:

A right triangle, with the hypotenuse = 18, one side = 7, and the other side = x.

Since this is a right triangle, use the pythagorean theorem to find the value for x.

let a = 7 for one side, and let c = 18 for the hypotenuse. And, let c = x for the other side.

The pythagorean theorem is: c^2 = a^2 + b^2.

18^2 = 7^2 + x^2324 = 49 +x^2

x^2 = 324 - 49 = 275So, x = sqrt(275) = 16.5 cm

3 0

2 years ago

Read 2 more answers

What is the equation of the line that passes through the point (-5,5) and has a slope of -1

max2010maxim [7]

Answer:

y - 5 = -(x + 5)

y - 5 = -x - 5

y = -x

7 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

_____

<em>Additional comment</em>

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

How can you use a mixed number ti write 11 feet as an equivalent measure in yards

svetoff [14.1K]

Answer: 3 2/3 Yards

Step-by-step Solution:

In order to solve this problem, you'll want to set up a conversion equation.

** 1 Yard = 3 Feet **

To convert these measurements you'll need to write this conversion factor as a conversion ratio. Your ratio will be 1 yard / 3 feet. This fraction is actually equal to 1, meaning we can multiply it by any number to convert the units without changing its value.

You can then solve by using simple division. I will attach a photo of the steps I did by hand.

** Canceling the units will help avoid confusion **

After you reach the 6th step, all you have to do to find your mixed number is see how many times 3 fits into 11.

3 can go into 11 3 times, with a remainder of 2. Your final answer should be 3 2/3 yards.

I hope this helps! c:

4 0

3 years ago