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3 years ago

Is the line y = 3x – 7 parallel or perpendicular to 3x + 9y = 9? Explain your answer.

Mathematics

1 answer:

Mama L [17]3 years ago

6 0

Answer:

perpendicular

Step-by-step explanation:

The slope of y = 3x - 7 is 3.

3x + 9y = 9 → 9y = -3x + 9 → y = -1/3 x + 1 so its slope is -1/3.

This means that they are perpendicular because the product of their slopes is -1.

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Write 6.7 in two other forms

salantis [7]

$6.7=6+0.7=6+\frac{7}{10}=\huge\boxed{6\frac{7}{10}}\\\\6.7\to\huge\boxed{six\ and\ seven\ tenths}$

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3 years ago

Read 2 more answers

Kelly bought 8 towels and spent $39.60 each towel cost the same amount, create an equation that can be used to determine the pri

S_A_V [24]

It could be 8x= 39.60

hope this helps :)

8 0

3 years ago

Which fraction is equivalent to a repeating decimal? A. 1/8 B. 2/8 C. 14/21 D. 3/10

saveliy_v [14]

Answer:

Step-by-step explanation:

14/21 = 2/3 = .666666666666666666666.....7

3 0

3 years ago

R is a point which is 13 units from the origin if its x co-ordinates is 12 find the possible values of the y co-ordinate

daser333 [38]

Answer:

given (0,0) and (12,y1)

the distance formula states taht

the distance between the points (x1,y1) and (x2,y2) is

given

D=13

x1=0, y1=0

x2=12

square both sides

minus 144 both sides

sqrt both sides

+/-5=y2

the points are

(12,5) and (12,-5)

Step-by-step explanation:

8 0

4 years ago

While traveling to and from a certain destination, you realized increasing your speed by 40 mph saved 4 hours on your return. If

Luden [163]

Answer:

The speed driven while returning is 88 mph.

Step-by-step explanation:

We are given that while traveling to and from a certain destination, you realized increasing your speed by 40 mph saved 4 hours on your return.

Also, the total distance of the roundtrip was 420 miles.

Let the speed driven while returning be 'x mph' which means that the speed driven while going was '(x - 40) mph' because it has been given that while returning we have increased the speed by 40 mph.

As we know that the Speed-Distance-Time formula is given by;

$\text {Speed} = \frac{\text{Distance}}{\text{Time}}$ or $\text {Time} = \frac{\text{Distance}}{\text{Speed}}$

So, according to the question;

$\frac{420}{x-40} -\frac{420}{x} = 4 \text{ hours}$ where Distance = 420 miles

$\frac{420x-420(x-40)}{x(x-40)} = 4$

$\frac{420x-420x+16800}{x^{2} -40x} = 4$

$\frac{16800}{x^{2} -40x} = 4$

$4x^{2} -160x= 16800$

$4x^{2} -160x- 16800=0$

$x^{2} -40x- 4200=0$

Now finding the roots of the above equation;

Here a = 1, b = -40 and c = -4200

$D = b^{2} -4ac$

= $(-40)^{2} -4(1)(-4200)$ = 18400

Now, the roots of a quadratic equation is given by;

$x = \frac{-b\pm \sqrt{D} }{2a}$

$x = \frac{-(-40)\pm \sqrt{18400} }{2\times 1}$

So, the two roots of x are : $x = \frac{40-\sqrt{18400} }{2}$ and $x = \frac{40+\sqrt{18400} }{2}$

Solving these two we get; $x = -47.8$ and $x = 87.8$

Here we ignore the negative value of x, so the speed driven while returning is 87.8 ≈ 88 mph.

8 0

3 years ago