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2 years ago

Explain how (-3) x (-3) = 9 using coupons as the real world example

Mathematics

2 answers:

klasskru [66]2 years ago

7 0

Answer:

a negative multiplied by a negative is always a positive

Step-by-step explanation:

so, -3 x -3 =9

iVinArrow [24]2 years ago

4 0

If you use two coupons that are each for $3 off, you will have saves a total of 9 dollars... hope this helped

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8. 36.8 = [11.5 – (2.5 X 3)]2

Anestetic [448]

Answer:

$[11.5-(2.5*3)]^2=16$

Step-by-step explanation:

We want to evaluate $[11.5-(2.5*3)]^2$

Let us evaluate within the parenthesis first:

$[11.5-(2.5*3)]^2=[11.5-(7.5)]^2$

$\implies [11.5-(2.5*3)]^2=[11.5-7.5]^2$

We again subtract within the bracket to obtain:

$[11.5-(2.5*3)]^2=[4]^2$

This finally gives us:

$[11.5-(2.5*3)]^2=16$

6 0

3 years ago

PLEASE HELP ME!! And this is about Unit conversions!!! BUT PLEASE HELP AND EXPLAIN THIS TO ME!!

prisoha [69]

Unit conversions will almost always fall into a division or multiplication problem. In this case we are being asked to convert a smaller unit to a larger one, so it will be a division problem.
The standard metric goes on the bottom of the fraction always, so 10/16 or 10÷16 is the problem.
10÷16= .625 pounds of cheese.

7 0

3 years ago

Read 2 more answers

Lisa walked 8 km more than Tim. Lisa walked twice as far as Tim. How far did each walk?

valentinak56 [21]

$x-\ Tim's\ distance\\\\
x+8-\ Lisa's\ distance\\\\
2x=x+8\ \ |Subtract\ x\\
2x-x=8\\
x=8\ \ -Tim\\
x+8=8+8=16- \ Lisa\\\\Lisa\ walked\ 16\ km\ and\ Tim\ 8km.
$

6 0

3 years ago

Consider the right triangular prism given AC = 9 cm

Oduvanchick [21]

Answer:

1 3 4 5

Step-by-step explanation:

3 0

3 years ago

Read 2 more answers

The life of a red bulb used in a traffic signal can be modeled using an exponential distribution with an average life of 24 mont

BartSMP [9]

Answer:

See steps below

Step-by-step explanation:

Let X be the random variable that measures the lifespan of a bulb.

If the random variable X is exponentially distributed and X has an average value of 24 month, then its probability density function is

$\bf f(x)=\frac{1}{24}e^{-x/24}\;(x\geq 0)$

and its cumulative distribution function (CDF) is

$\bf P(X\leq t)=\int_{0}^{t} f(x)dx=1-e^{-t/24}$

• What is probability that the red bulb will need to be replaced at the first inspection?

The probability that the bulb fails the first year is

$\bf P(X\leq 12)=1-e^{-12/24}=1-e^{-0.5}=0.39347$

• If the bulb is in good condition at the end of 18 months, what is the probability that the bulb will be in good condition at the end of 24 months?

Let A and B be the events,

A = “The bulb will last at least 24 months”

B = “The bulb will last at least 18 months”

We want to find P(A | B).

By definition P(A | B) = P(A∩B)P(B)

but B⊂A, so A∩B = B and

$\bf P(A | B) = P(B)P(B) = (P(B))^2$

We have

$\bf P(B)=P(X>18)=1-P(X\leq 18)=1-(1-e^{-18/24})=e^{-3/4}=0.47237$

hence,

$\bf P(A | B)=(P(B))^2=(0.47237)^2=0.22313$

• If the signal has six red bulbs, what is the probability that at least one of them needs replacement at the first inspection? Assume distribution of lifetime of each bulb is independent

If the distribution of lifetime of each bulb is independent, then we have here a binomial distribution of six trials with probability of “success” (one bulb needs replacement at the first inspection) p = 0.39347

Now the probability that exactly k bulbs need replacement is

$\bf \binom{6}{k}(0.39347)^k(1-0.39347)^{6-k}$

<em>Probability that at least one of them needs replacement at the first inspection = 1- probability that none of them needs replacement at the first inspection. </em>

This means that,

<em>Probability that at least one of them needs replacement at the first inspection = </em>

$\bf 1-\binom{6}{0}(0.39347)^0(1-0.39347)^{6}=1-(0.60653)^6=0.95021$

5 0

3 years ago