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3 years ago

Mr Thompson, Please help!

Mathematics

1 answer:

BARSIC [14]3 years ago

8 0

Problem 1

<h3>Answer: Choice C) x^2-4 </h3>

Explanation:

Use the difference of squares rule here.

That rule says (a-b)(a+b) = a^2-b^2

In this case, a = x and b = 2.

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Problem 2

<h3>Answer: Choice B) 2x^2+7x+5</h3>

Work Shown:

(2x+5)(x+1)

y(x+1) ..... let y = 2x+5

xy+y

x(y) + 1(y)

x(2x+5) + 1(2x+5) ... plug in y = 2x+5

2x^2+5x+2x+5

2x^2+7x+5

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Problem 3

<h3>Answer: Choice A) -x^2-5x+7</h3>

Explanation:

The standard form of a quadratic is ax^2+bx+c, where a,b,c are real numbers. In the case of choice A, we have a = -1, b = -5, c = 7.

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Problem 4

<h3>Answer: Choice D</h3>

Explanation:

Along the top we have three green rectangles. If each of them are of length x, then we have x+x+x = 3x so far. Then adding on a yellow piece of 1 unit leads to 3x+1 as the total horizontal width across the top.

Similarly, along the left side we have 1 green portion and 2 yellow leading to x+2. So this shows why this diagram represents (3x+1)(x+2)

A rectangle must be formed with the smaller pieces glued together. We cannot have any gaps or overlaps. The reason we're aiming for a rectangle is because the area of a rectangle is length*width. Think of (3x+1) as the length and (x+2) as the width.

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When completely factored, 3x2−48 equals -

Svetlanka [38]

Answer:

Step-by-step explanation:

If you are asking what 3x2-48 is, then the rules of Pemdas would be relevant in this.

First we would multiply. So, 3 times 2 is 6.

Then, 6-48 is -42

5 0

3 years ago

Vote for the best representation of 7 and 95/125

Sergio039 [100]

95/125 = 0.76
7 96/125 = 7.76

hope this helps @[email protected]

7 0

4 years ago

PLEASE HELP ASAP A popular video game claims that the average time needed to reach level 10 Paladin is 3 hours with a standard d

sukhopar [10]

I'm guessing 1%

0.4X2.5=1

6 0

3 years ago

Need help with stats!

Brut [27]

Answer:

a) 1,440 ways

b) 59,280 or 64,000

Step-by-step explanation:

a) Aircraft boarding.

8 people, 2 in first class, boarding first, then 8 economy class.

The 2 people in first class board first, but they can board as AB or BA... so 2 ways here.

For the 6 economy class passengers, we have a permutation of 6 out of 6, so 720, as follows:

$P(6,6) = \frac{6!}{(6 - 6)!} = 6! = 720$

Since the two are independent, we multiply them to have a global number of ways: 2 * 720 = 1,440 different ways for the 8 passengers to board that plane.

b) combination lock.

Here we do have a little problem... the question doesn't specify if the 3 numbers are different numbers of not. So, we'll calculate both:

Numbers go from 1 to 40 inclusively... so 40 possibilities.

Normally, in a combination lock, the numbers are different, so let's start with that one:

First number: 40 options available

Second number: 39 options available (cannot take the first one again)

Third number: 38 different options (can't take First or Second number again)

Overall, we then have 40 * 39 * 38 = 59,280 different lock combinations.

If we can pick pick the same number twice:

First number: 40 options available

Second number: 40 options available

Third number: 40 options available

Overall 40 * 40 * 40 = 64,000 different lock combinations

8 0

3 years ago

Need help with this one question please!!!

Ede4ka [16]

<u>Find the graph of the equation y = x² - 4x + 4.</u>

This is in the general form y = ax² + bx + c

1.) Graph shape. For parabolas, if the a-value is positive, the graph opens upward, creating a U-shaped graph. If the a-value is negative, the graph will open downwards.

Our equation has a positive a-value, which means our graph will open upwards in a U shape. This rules out options (a) and (d), as they both open downwards.

2.) The axis of symmetry. To find the axis of symmetry (the middle of the graph, and in this case, its x-coordinate), use the formula $x = -\frac{b}{2a}$ .

$x = -\frac{(-4)}{2(1)}$

$x = -(-2) = 2$

The vertex of the graph is at x = 2. Graphs (b) and (d) both have a vertex at x = 2, but we already ruled out (d) because it opens in the wrong direction for our equation. This means the correct option must be option (b).

Note: The equation of the parabola tells us that the y-intercept of the graph is at y = 4. We can see that option (b) is the only option that has a y-int at 4. This allows us to check our work.

4 0

3 years ago