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3 years ago

The equation 4(x – 3)2 – 5 = 139 has two solutions: one positive and one negative. What is the

Mathematics

1 answer:

AlekseyPX3 years ago

3 0

Answer:

Step-by-step explanation:

4(x-3)2-5 = 139

(4x-12)-5=139

-20x + 60 = 139

-20x +60 - (60) = 139- 60

-20x = 79 divide both sides by -20

x = -3.95

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Explain how negative powers of 10 can be helpful when writing and comparing small numbers

Luba_88 [7]

Answer:

See explanation

Step-by-step explanation:

Powers of 10 is a very useful way of writing down large or small numbers.

Instead of having lots of zeros, you show how many powers of 10 will make that many zeros.

When you work with small numbers, you should use the negative powers of 10. Just remember for negative powers of 10, move the decimal point to the left. For example,

$0.36=3.6\cdot 10^{-1}\ [\text{Move the decimal point one place to the left}]\\ \\0.036=3.6\times 10^{-2}\ [\text{Move the decimal point two places to the left}]\\ \\0.0036=3.6\times 10^{-3}\ [\text{Move the decimal point three places to the left}]\\ \\...$

When comparing small numbers, write these numbers in scientific notation (only one non-xero digit must be before point) and then

if the powers of 10 are the same in compared numbers are the same, just compare the numbers which are multiplied by these powers of 10. For example, $3.6\times 10^{-6}>2.6\times 10{-6},$ because powers are the same (-6) and $3.6>2.6$
if the powers are different, then the smaller is power, the smaller is number (number with the smaller negative power has more places after decimal point). For example, $3.6\times 10^{-6}> 2.6\times 10^{-7},$ because $-6>-7$

8 0

3 years ago

Pediatricians prescribe 5mL of cough syrup for every 25lb of a child's weight. How many mililiters of cough syrup will the docto

Marianna [84]

Answer:

9 ml

Step-by-step explanation:

The Pediatrician prescribes 5 milliliters of cough syrup for every 25 lb of child weight.

Now, the weight of Jocelyn is 45 lb.

If the rate of prescribing the cough syrup in ml per weight of patients remains constant,

Then we can use the unitary method to get the amount of cough syrup prescribed by the Pediatrician for Jocelyn, and that will be

$\frac{5*45}{25} =9$ ml. (Answer)

3 0

3 years ago

A population of ants triples every week. If the population starts at 7, how many ants will there be after 7 weeks?

Harrizon [31]

Answer:

147 ants

Step-by-step explanation:

7 times 3=21 21 times 7= 147

6 0

3 years ago

Read 2 more answers

A real estate agent has 8 master keys to open several new homes. Only 1 master key will open any given house. If 40% of these ho

riadik2000 [5.3K]

Answer:

Step-by-step explanation:

Suppose F represents the value that a room is unlocked.

Then, we can assume that the probability of unlocked homes is:

P(unlocked homes) = P(U)

P(unlocked homes) = 40%

P(unlocked homes) = 0.40

Also, let us represent the value of the locked room with G.

P(locked homes) = P(G)

P(locked homes) = (1 - 0.40)

P(locked homes) = 0.60

Let the probability of selecting a correct key be P(S)

It implies that for the agent to use 3 keys, we have a combination of $^8C_3$ possible ways for the set of keys.

Now; since only one will open the house, then:

P(select correct key) = P(S)

$P(S) = \dfrac{ (^1_1) (^7_2) }{ ^8_3 }$

$P(S) = \dfrac{21}{56}$

P(S) = 0.375

Finally, for the real estate agent to have access to specific homes supposing the agent select three master keys at random prior to the time he left his office, Then:

P(F ∪ (G∩S) = P(F) + P(G∩S)

P(F ∪ (G∩S) = P(F) + P(G) × P(S)

P(F ∪ (G∩S) = 0.40 + (0.60×0.375)

P(F ∪ (G∩S) = 0.40 + 0.225

P(F ∪ (G∩S) =0.625

5 0

2 years ago

Helppppppppppppppppp

bixtya [17]

The answer is C. Good luck

8 0

3 years ago

Read 2 more answers