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3 years ago

Suppose that Y varies directly with X andY equals 12 when X equals -2 what is X when Y equals -6

Mathematics

1 answer:

VLD [36.1K]3 years ago

4 0

Answer:

$x=1$

Step-by-step explanation:

A direct variation equation has the following format:

$y=kx$

Where k is a constant.

We know that y is 12 when x is -2. Thus, substitute:

$12=-2k$

Divide both sides by -2:

$k=-6$

So, our direct variation equations is:

$y=-6x$

To find what x is when y equals -6, substitute in -6 for y:

$-6=-6x$

Divide both sides by -6:

$x=1$

So, our answer is 1 :)

You might be interested in

13, 5, 4, 9, 7, 14, 4 The deviations are _____.

fenix001 [56]

Answer:

B."5, -3, -4, 1, -1, 6, -4"

Step-by-step explanation:

We are given that

13,5,4,9,7,14,4

We have to find the deviation.

Mean= $\frac{sum\;of\;data}{total\;number\;of\;data}$

Using the formula

$Mean,\mu=\frac{13+5+4+9+7+14+4}{7}$

$Mean,\mu=\frac{56}{7}=8$

Deviation= $x_i-\mu$

$x_i-\mu$

13 5

5 -3

4 - 4

9 1

7 -1

14 6

4 - 4

Hence, option B is correct.

7 0

3 years ago

3х - 30 = у 7y - 6 = 3х

mars1129 [50]

Answer:

Step-by-step explanation:

This one is simple substitution... at least, substitution is the easiest method. The first equation is 3x – 30 = y and the second is 7y – 6 = 3x

As I look, I see 3 ways to use substitution to solve this:

substitute 7y – 6 for 3x
substitute 3x – 30 for y
solve 3x – 30 = y for 3x and make it equal to 7y – 6

We're going to only use 1 method for the sake of time. Try the other two on your own. Assuming you don't make any mistakes, they will work.

Method 1:

3x – 30 = y

7y – 6 = 3x — initial system of equations

7y – 6 – 30 = y — substitute 7y – 6 for 3x

7y – 6 – 30 = y — marking like terms, bold for constants, underlined for variables

7y – 36 = y — combining the constants and simplifying

Here, you could diverge into multiple paths: add 36 to both sides, subtract y from both sides, divide by 6 OR subtract 7y from both sides and divide by –6 . For the sake of time, I'm subtracting 7y, though I don't like dealing with negatives.

7y – 7y – 36 = y – 7y — subtract 7y from both sides

–36 = –6y — simplify

–36 ÷ –6 = –6y ÷ –6 — divide by –6 on both sides

y = 6 — simplify

Again, we can diverge here: substitute y into 3x – 30 = y or substitute y into 7y – 6 = 3x

I'm going to choose 3x – 30 = y but it will work either way, should you take the time (if you have it) to chase down every path this problem can take.

3x – 30 = y — initial equation

3x – 30 = 6 — substitute 6 for y

3x – 30 + 30 = 6 + 30 — add 30 to both sides to isolate 3x

3x = 36 — simplify the expression

3x ÷ 3 = 36 ÷ 3 — divide both sides by 3 to isolate x

x = 12 — simplify

So, we have x = 12 and y = 6 . We know they work for 3x – 30 = y but not if they work for 7y – 6 = 3x . Let's substitute those in to see if (12, 6) really is the solution point.

7y – 6 = 3x — original equation

7(6) – 6 ≟ 3(12) — substitute 6 for y and 12 for x

42 – 6 ≟ 36 — simplify by multiplying

36 = 36 ✔ — simplify by combining like terms on left side

Success! It works! We have found our solution!

I hope this helps increase your understanding of the concept. Have a great day!

8 0

3 years ago

A baker sells cookies for $1.50 each. If a minimum of two dozen cookies is ordered, the baker gives a 40% discount for each cook

kenny6666 [7]

I don't see the expression below.
Since the 40% discount applies to the number of cookies sold above 2 dozen, or 24, then if the number of cookies is c, then c - 24 is the number of cookies above 2 dozen. Answer is B.

7 0

3 years ago

10.04 × 8.8= ? can you help me again please

ANEK [815]

Answer:

10.04 × 8.8 =?, ? = 88.352 :)

7 0

3 years ago

Read 2 more answers

Can you help me on both of this problems

AlekseyPX

Answer: