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4 years ago

Find the values of y which makes the expression (2y + 7) /(y2 - 2y - 15) undefined?

Mathematics

1 answer:

sammy [17]4 years ago

8 0

The given expression becomes undefined when y=5 or y = -3. The answer is option D.

Step-by-step explanation:

The value of the given expression becomes undefined when the denominator equals 0.

Hence to find the value of y which makes the expression undefined, we can equate the value of the denominator to zero and solve it .

Step 1

Equate the denominator to 0.

y^{2} - 2y -15 = 0

Step 2

Solve the above equation to get the value of y.

y^{2} - 2y -15 = 0

=> (y-5)(y+3) =0 [ Roots of the quadratic equation]

=> y = 5 or y = -3.

Hence when y = 5 or y = -3 the denominator becomes 0, which makes the expression (2y+7)/0 and hence it is undefined.

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Mariah's earnings rate can be described in dollars per hour or hours per dollar. Mariah earns $10 for each hour she works at a m

weeeeeb [17]

Answer:

dollars per hour rate = $10

hours per dollar = 6 minutes 15 seconds

Step-by-step explanation:

Take note that one is singular (dollar) without an 's', and the other is plural (dollars). Thus, since her dollars per hour rate tells us how much she will earn for each hour of work, we would expect her hours per dollar rate to tell us how much she has to work in minutes to earn a single dollar ($1).

If we divide $\frac{10}{60 minutes}$ = $0.16 which indicates how much she earns for every minute she works at the theater. Further dividing this value into 1 minute we find the hour per dollar rate 1/0.16 = 6.25. minutes.

7 0

3 years ago

Find the next number in the sequence. 25, 36, 49, 64, ...

ra1l [238]

Answer:

81

Step-by-step explanation:

25, 36, 49, 64, ...

36 - 25 = 11

49 - 36 = 13 = 11 + 2

64 - 49 = 15 = 13 + 2

64 + 15 + 2 = 81

6 0

3 years ago

Read 2 more answers

Given that 1 inch = 2.54 cm, how many centimeters are there in 3 feet? Answers may be written using decimal form and should be r

Olin [163]

Answer:

There is 91.44 centimeters in 3 feet.

Step-by-step explanation:

First, you would have to know that there are 12 inches in 1 feet. So, if you do 12 x 3, you would get 36 inches to equal 3 feet. Then, you can do 36 x 2.54 and get your answer of 91.44 centimeters.

5 0

3 years ago

Make y the subject of the formula W= x squared - 2yz

AveGali [126]

Answer:

The formula $y = \frac{x^{2} }{2z} + \frac{W}{2z}$

Step-by-step explanation:

Explanation

Given W = x² - 2 y z

2 y z = x² + W

Dividing '2z' on both sides , we get

$\frac{2yz}{2z} = \frac{x^{2} + W}{2z}$

⇒ $y = \frac{x^{2} }{2z} + \frac{W}{2z}$

4 0

3 years ago

How to classify this conic ecwation 4x^2+9y^2-54y-63=0

MArishka [77]

This looks like an ellipse.
Complete the square for y: 9(y²-6y-7)=9(y²-6y+9-9-7)=9((y-3)²-16).
Rewrite the equation:
4x²+9(y-3)²-144=0; 4x²/144+9(y-3)²/144=1; x²/36+(y-3)²/16=1.
Standard equation of an ellipse is (x-h)²/a²+(y-k)²/b²=1, where (h,k) is the origin or centre.
This is the equation of an ellipse with centre (0,3), a=6 and b=4 (semimajor and semiminor axes).

6 0

3 years ago