Mathematics, 19.08.2020 18:01, dbenitezmontoya3

Please help me asap 10 points.

Answers: 1

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Answers

answered: 21ltilley

Step-by-step explanation:

1).

$\frac{x}{8} = \frac{9}{24}$

Cross multiply

We have

24x = 72

Divide both sides by 24

That's

$\frac{24x}{24} = \frac{72}{24}$

We have the answer as

x = 32).

3x² + 2x - 10

when x = - 1

Substitute the value of x into the expression

That's

3(-1)² + 2(-1) - 10

= 3 - 2 - 10

We have the answer as

- 9

When x = 0

That's

3(0) + 2(0) - 10

= - 10

When x = 1

That's

3(1)² + 2(1) - 10

= 3 + 2 - 10

= 5 - 10

= - 53).

$\sqrt{( - 9)}$

First of all apply the radical rule

That's

$\sqrt{ - a} = \sqrt{ - 1} \times \sqrt{a}$

So we have

$\sqrt{ - 9} = \sqrt{ - 1} \times \sqrt{9}$

Using the imaginary rule

That's

$\sqrt{ - 1} = i$

We have

$\sqrt{9} \times i$

We have the final answer as

3i 4).

$\frac{1}{x}$

when x = 0

We have

$\frac{1}{0} = 0$

when x = 1

$\frac{1}{1} = 1$

when x = 2

We have

$\frac{1}{2}$

Hope this helps you

answered: Guest

step-by-step explanation:

30% of $420 is 0.30($420) = $126 and $420 + $126 = $546.

or, 130% of $420 is 1.3($420) = $546.

notice that this is not the $600 original list price with which we started.

why doesn't this work?

the method does not work because 30% of $420 is not the same amount as the 30% of $600. it may seem obvious when stated this way, but it is a very common error made on problems of this type. we cannot just use the same percent and get back to the original amount because we are taking that percent of a different value.

to work problems of this type correctly, it is generally best to write an equation for the situation and then solve.

example: since (100% – 30%)(original price) = (sale price)

70% of the (original price) is $420.

0.7x = 420

equation image indicator

x = 600

the original cost was $600.

we may also solve this problem using the two-step method. working the problem in two steps requires us to use more algebra skills. we have to know that x = 1x (identity property of multiplicationtext annotation indicator) and that 1x – 0.3x = 0.7x (subtracting like terms). then we solve the problem as follows:

(original price) – 30%(original price) = sale price

x – 0.3x = 420

0.7x = $420

equation image indicator

x = 600

the original cost was $600.

note that with both of the above methods we do obtain the correct original amount.

example: after a 5% pay raise, hermione is earning $22,680 per year. what was she earning before the pay raise?

105% of (original salary) = current salary

1.05x = 22,680

equation image indicator

x = 21,600