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3 years ago

Please solve the following quadratic equation and show your work: x^2 -x =30

1 answer:

8 0

Rewriting the equation as a quadratic equation equal to zero:
x^2 - x - 30 = 0
We need two numbers whose sum is -1 and whose product is -30. In this case, it would have to be 5 and -6. Therefore we can also write our equation in the factored form
(x + 5)(x - 6) = 0
Now we have a product of two expressions that is equal to zero, which means any x value that makes either (x + 5) or (x - 6) zero will make their product zero.
x + 5 = 0 => x = -5
x - 6 = 0 => x = 6
Therefore, our solutions are x = -5 and x = 6.

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The diagram at the right shows the orthocenter of an acute triangle. Drag vertex C to form a right triangle and an obtuse triang

galina1969 [7]

Answer:

1,3,5 is the answer

Step-by-step explanation:

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4 years ago

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A device contains two circuits. The second circuit is a backup for the first, so the second is used only when the first has fail

Wittaler [7]

Answer:

Step-by-step explanation:

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3 years ago

Please help me solve this problem

Stells [14]

Answer:

$180

Step-by-step explanation:

To solve, we can set up a proportion and solve.

You earn $45 for 7.5 hours of work, and you earn $ x for 30 hours of work

45/7.5=x/30

Cross multiply

45*30=7.5*x

1350=7.5x

To solve for x, we need to get x by itself. It is being multiplied by 7.5. To undo this, divide both sides by 7.5

1350/7.5=7.5x/7.5

180=x

So, for 30 hours of work, you would earn $180

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3 years ago

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If you were asked to convert 75 m/s to km/hr, which conversation factors would you need to use. Select all that apply.

Vilka [71]

Answer:

You need to use A, B, and C.

Step-by-step explanation:

Let's treat the units as variables. I'll illustrate why in a moment.

$75 m/s =\frac{75m}{1s} \\\\\frac{75m}{1s}*\frac{1km}{1000m}=\frac{75m*km}{1000m*s}\\\\\frac{75m*km}{1000m*s}*\frac{60s}{1min}=\frac{(75*60)m*km*s}{1000m*s*min}\\\\\frac{4500m*km*s}{1000m*s*min}*\frac{60min}{1h}=\frac{4500m*km*s*min}{1000m*s*min*h}$

Now, as you can see, we have a giant mess of units to deal with. This is where we can treat the units like separate variables and use a bit of algebra to make our lives easier:

$\frac{4500m*km*s*min}{1000m*s*min*h}=\frac{4500}{1000}*\frac{m*km*s*min}{m*s*min*h}\\\\\frac{4500}{1000}*\frac{m*km*s*min}{m*s*min*h}=\frac{4500}{1000}*\frac{m}{m}*\frac{km}{1}*\frac{s}{s}*\frac{min}{min}*\frac{1}{h}\\\\\frac{4500}{1000}*\frac{m}{m}*\frac{km}{1}*\frac{s}{s}*\frac{min}{min}*\frac{1}{h}=\frac{4500}{1000}*\frac{m*km*s*min}{m*s*min*h}=\frac{4500}{1000}*1*\frac{km}{1}*1*1*\frac{1}{h}\\\\\frac{4500}{1000}*1*\frac{km}{1}*1*1*\frac{1}{h}=\frac{4500}{1000}*\frac{km}{h}\\$

$\frac{4500}{1000}*\frac{km}{h}=\frac{45}{1}*\frac{km}{h}=45 \frac{km}{h}$

So, backtracking through that entire mess, we had to use $\frac{1km}{1000m} ,\frac{60s}{1min} ,\frac{60min}{1h}$ .

These correspond to the options of A, C, and B accordingly.

So you need to use A, B, and C.

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3 years ago

Eight subtracted from three times a number is 7

Jobisdone [24]

3x-8(+8)=7(+8)
3x/3=15/3
x=3

4 0

3 years ago