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3 years ago

(d) Factorise x² – 100

Mathematics

1 answer:

inessss [21]3 years ago

7 0

Answer:

Step-by-step explanation:

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Pls help i will give brainliest and 5 stars

IceJOKER [234]

Answer:

See attached diagram

Step-by-step explanation:

See attached picture....I assumed -3% was really just -3

8 0

2 years ago

Which ordered pair is a solution of the inequality y < 3x + 1?

diamong [38]

Answer:

C. (1, -3)

Step-by-step explanation:

<em>My thought process: Guess and check by plugging in each ordered pair.</em>

A) -2 < 3(-3) +1

-2 < -8 FALSE

B) 14 < 3(3) + 1

14 < 10 FALSE

C) -3 < 3(1) + 1

-3 < 4 TRUE

3 0

3 years ago

A store marks up all of their merchandise by 70%. The floor price of a scarf is $117.25.

KiRa [710]

Answer:

$68.97

Step-by-step explanation:

Markup is the difference between the cost of an item and the price at which it is sold:

cost price + markup = selling price

Here, the markup is said to be 70%. The base for that percentage can be either the cost price or the selling price. The way this question is worded suggests the markup is 70% of the cost price.

So, we have ...

cost price + 0.70 × cost price = selling price

cost price × (1 + 0.70) = selling price

Then, to find the cost price, we can divide by its coefficient in this equation. Doing that gives ...

cost price = (selling price)/1.70

cost price = $117.25/1.70 = $68.97

The store's purchase price before the markup for this item was $68.97.

4 0

3 years ago

A doctor wants to estimate the mean HDL cholesterol of all 20- to 29-year-old females. How many subjects are needed to estimat

REY [17]

(a) 404 subjects are needed to estimate the mean HDL cholesterol within 2 points with 99% confidence.

(b) When the confidence level decreases to 95%, the number of subjects decreases from 404 to 234.

<u>Explanation:</u>

Given:

σ = 15.6

Let the number of subjects be n

(a)

When the confidence level is 99%, then z = 2.576

E = 2

We know:

$n = [\frac{z X s}{E}]^2$

On substituting the value, we get:

$n = [\frac{2.576 X 15.6}{2} ]^2\\\\n = 403.7$

Thus, 404 subjects are needed to estimate the mean HDL cholesterol within 2 points with 99% confidence.

(b)

When the confidence level is 95%, then z = 1.96

E = 2

We know:

$n = [\frac{z X s}{E}]^2$

On substituting the value, we get:

$n = [\frac{1.96 X 15.6}{2} ]^2\\\\n = 233.7$

n = 234

Thus, when the confidence level decreases to 95%, the number of subjects decreases from 404 to 234.

8 0

3 years ago

The area of a rectangle is 112 units squared.

kifflom [539]

Answer:

Step-by-step explanation:

The area for a rectangle is A = LW. We know the area and we also know the length. We are solving for the width.

$112=7\sqrt{x}$ and

$16=\sqrt{x}$

Siince the width is given as the square root of x, and the square root of x is equal to 16, then the width is 16. Now to find the value of x from the last statement in our equation. If

$16=\sqrt{x}$ and we want to solve for x, we will square both sides, since squaring undoes a square root. Since this is an equation, we have to square both sides.

256 = x

7 0

4 years ago