NEED HELP !!!!!!!!!!!!!!!!!!!!!!!

emmasim [6.3K]

Get the b all alone on one side of the inequality. To do this, we can divide both sides by 5.

5b / 5 ≤ -15 / 5
b ≤ -3

So, that means b has to be less than or equal to -3.

In interval notation it would look like [-3, -∞)

In a set builder notation: {x | x ∈ R, x ≤ -3}

Which is read as the set of all x, such that, x is a member of the real numbers and x is less than or equal to -3.

6 0

3 years ago

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Find the slope of the line through the pair of points. A(2, –3), P(2, 9)

Flauer [41]

The slope: $m=\dfrac{y_2-y_1}{x_2-x_1}$

$A(2;-3)\to x_1=2;\ y_1=-3\\P(2;\ 9)\to x_2=2;\ y_2=9\\\\subtitute:\\\\m=\dfrac{9-(-3)}{2-2}=\dfrac{12}{0}!!!$

<span>The denominator can not be <span>zero!

Conclusion: The slope is undenfined.
</span></span>

6 0

3 years ago

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I need some help with problems 25 and 26

Vinil7 [7]

I didn't figure out 25 but number 26 would be mdivide by 6 is 3. Since one week the persob ran 6 mi and that is 1/3 of the month. So m divided by 6 must be 3.

6 0

3 years ago

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Which of the following solutions to the inequality -7x+14>-3x -6? Select all that apply

alexgriva [62]

I went thru it and im pretty sure that only these work

-10

-5

-3

3 0

2 years ago

The vertices of a parallelogram are A(x1, y1), B(x2, y2), C(x3, y3), and D(x4, y4). Which of the following must be true if paral

Iteru [2.4K]

The answer is really none of the above, because all of these have divisions by difference in x, and there are perfectly fine rectangles where those will mean dividing by zero.

To do the problem the way they want us to, we note segments with the same slope are parallel (or collinear); segments with slopes which multiply to -1 are perpendicular.

Let's figure out what each choice is trying to tell us by translating it into parallel and perpendicular. Remember A is point 1, ...

A. ((y_4-y_3)/(x_4-x_3)= (y_3-y_2)/(x_3-x_2)) and ((y_4-y_3)/(x_4-x_3)×(y_3-y_2)/(x_3-x_2))=-1

translated, that's CD║BC and CD⊥BC - contradictory; second half right

B. (y_4-y_3)/(x_4-x_3)= (y_2-y_1)/(x_2-x_1) and ((y_4-y_3)/(x_4-x_3)×(y_2-y_1)/(x_2-x_1))=-1

CD ║ AB and CD ⊥ AB - only the parallelogram half is right

C. (y_4-y_3)/(x_4-x_3)= (y_2-y_1)/(x_2-x_1) and (y_4-y_3)/(x_4-x_3)×(y_3-y_2)/(x_3-x_2)=-1

CD║AB and CD⊥BC - that's TRUE

D. (y_4-y_3)/(x_4-x_3)= (y_3-y_1)/(x_3-x_1) and (y_4-y_3)/(x_4-x_3)×(y_2-y_1)/(x_2-x_1)=-1

CD║AC and CD⊥AB - nope

Answer: C

The way I'd get the proper expression is with the dot product.

A parallelogram is a rectangle when adjacent sides are perpendicular. It only takes one right angle to make them all right.

Two sides are perpendicular when the dot product of their direction vectors is zero. All the answers have $y_4 - y_3$ so one side is CD. The other side must be BC or AD; AD would give $y_4 - y_1$ terms which don't appear among the answer, so let's go with BC.