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3 years ago

Suppose that XNY are in rational numbers such that x>y. Which of the following inequalities must be true

Mathematics

1 answer:

igomit [66]3 years ago

8 0

Answer:

D. 2x > 2y

Step-by-step explanation:

This question illustrates some of the difficulties you can run into with inequalities.

Consider each of the expressions when x = 1 and y = -2. We know that

x > y

1 > -2

A. x^2 = 1, y^2 = 4 . . . . x^2 > y^2 is not true

B. -x = -1, -y = 2 . . . . -x > -y is not true

C. 1/x = 1/1 = 1, 1/y = 1/-2 = -1/2 . . . . 1/x > 1/y is true

Now consider x=2, y=1. x > y because 2 > 1, but ...

1/x = 1/2, 1/y = 1 . . . . 1/x > 1/y is not true

D. We know that multiplying the numbers by 2 only stretches them apart on the number line. It does not change their order. For our example, ...

2x = 2, 2y = -4 . . . . 2 > -4 is true

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you make a necklace using blue, purple and green beads in a ratio of 1:1:2. you use a total of 168 beads. How many green beads a

vesna_86 [32]

The answer is 84 green beads.

To get that you need to do 168 divide by 4 (four because I look at it like this 1:1:2 is like 1:1:1:1) That answer is 4 then double that and you get 84.

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3 years ago

Read 2 more answers

Is (x-4) a factor of f(x) = x3 - 2x2 + 5x + 1? Use either the remainder theorem or the factor theorem to explain your reasoning.

Virty [35]

Answer:

(x-4) is not a factor of f(x)=x³-2x²+5x+1

Step-by-step explanation:

Uding the remainder theorem,(x-4) is a factor if the remainder is 0

Plug in x=4

(4)³-2(4)²+5(4)+1

64-32+20+1

64-53

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3 years ago

Simplify completely quantity x squared plus 4 x minus 45 all over x squared plus 10 x plus 9 and find the restrictions on the va

Brums [2.3K]

Answer:

A) Quantity x minus 5 over quantity x plus 1, where x≠-1 and x≠-9

Step-by-step explanation:

$\frac{x^2 + 4x - 45}{x^2 + 10x + 9}$

Simplifying the numerator first:

x² + 4x - 45 using the quadratic formula you get;

(x - 5)(x + 9)

Then simplifying the denominator x² + 10x + 9 using a quadratic formula you get;

(x + 1)(x + 9)

Dividing the numerator and denominator now gives;

$\frac{(x - 5)(x + 9)}{(x + 1)(x + 9)}$

Cancelling (x + 9) throughout leaves you with;

$\frac{x - 5}{x + 1}$

The only restrictions here is if x = 1 and 9 which will give an undefined answer.

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3 years ago

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Seth just opened a checking account. His account includes an ATM card. What will he NOT be able to do with his card?

OverLord2011 [107]

Answer:

Option a

Step-by-step explanation:

Given that Seth just opened a checking account. His account includes an ATM card.

With ATM card

d) he can withdraw money from any ATM centre provided sufficient balance is kept in his checking account

b) he can deposit money for fixed denominations normally in multiples of 100 in the ATM centre with ATM card

c) he can give the card with pin in any shop to purchase an item instead of paying cash.

Hence b,c,d are not right answers.

a) transfer money is not possible using ATM card.

Only with netbanking transfer of money is possible

Option a is right answer

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3 years ago

What is the equation of the line that is parallel to the line y=2x+3 and passes through the point (-2,1)

Lerok [7]

Answer:

y= 2x+5

Step-by-step explanation:

The equation of a line is usually written in the form of y=mx+c, where m is the gradient and c is the y-intercept.

Parallel lines have the same gradient. Hence m=2.

Subst. m=2 into the equation:

y=2x +c

Now substitute a coordinate.

When x= -2, y=1,

1= 2(-2) +c

1= -4 +c

c= 1 +4

c=5

Thus, the equation of the line is y= 2x +5.

3 0

3 years ago