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3 years ago

Choose the correct simplification of the expression b5 ⋅ b4

Mathematics

2 answers:

Pachacha [2.7K]3 years ago

6 0

Answer:

$b^5 \cdot b^4=b^9$

Step-by-step explanation:

the correct simplification of the expression $b^5 \cdot b^4$

To multiply the exponents we use exponential property

$a^m \cdot a^n = a^{m+n}$

when the base are same and the exponents are in multiplication then we add the exponents.

$b^5 \cdot b^4=b^{5+4}$

We add the exponents 4+5 becomes 9

$b^5 \cdot b^4=b^9$

Andreas93 [3]3 years ago

3 0

20 * b(squared) would be the simplification of b5 * b4
You are just multiplying the two number together. You just have to remember that b4 is just b * 4... So b * 4 * b * 5 would equal 20 * b squared

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Kent walked to the bus stop, then sat and waited until the bus arrived. He rode the bus for 25 minutes, then walked the last 3 b

Vlad [161]

Answer:

The first graph best represent the given scenario.

Step-by-step explanation:

Given that Kent walked to the bus stop, then sat and waited until the bus arrived. He rode the bus for 25 minutes, then walked the last 3 blocks to work. we have to find which graph best represent the scenario.

In the first graph, it is given The line increases for 10 minutes means the distance as well as time increases i.e Kent walked for 10 minutes then, stays horizontal for 15 minutes means no distance covered i.e stop or wait for 15 minutes. After that graph increases rapidly for another 25 minutes, that means rode the bus for 25 minutes then increases slowly for 5 minutes indicate walked to work.

The above graph best represent the scenario.

All three option is analysed by graphing which doesn't show the above given scenario.

8 0

3 years ago

Read 2 more answers

A certain virus infects one in every 400 people. A test used to detect the virus in a person is positive 90% of the time if the

Ahat [919]

Answer:Given:

P(A)=1/400

P(B|A)=9/10

P(B|~A)=1/10

By the law of complements,

P(~A)=1-P(A)=399/400

By the law of total probability,

P(B)=P(B|A)*P(A)+P(B|A)*P(~A)

=(9/10)*(1/400)+(1/10)*(399/400)

=51/500

Note: get used to working in fraction when doing probability.

(a) Find P(A|B):

By Baye's Theorem,

P(A|B)

=P(B|A)*P(A)/P(B)

=(9/10)*(1/400)/(51/500)

=3/136

(b) Find P(~A|~B)

We know that

P(~A)=1-P(A)=399/400

P(~B)=1-P(B)=133/136

P(A∩B)

=P(B|A)*P(A) [def. of cond. prob.]

=9/10*(1/400)

=9/4000

P(A∪B)

=P(A)+P(B)-P(A∩B)

=1/400+51/500-9/4000

=409/4000

P(~A|~B)

=P(~A∩~B)/P(~B)

=P(~A∪B)/P(~B)

=(1-P(A∪B)/(1-P(B)) [ law of complements ]

=(3591/4000) ÷ (449/500)

=3591/3592

The results can be easily verified using a contingency table for a random sample of 4000 persons (assuming outcomes correspond exactly to probability):

===....B...~B...TOT

..A . 9 . . 1 . . 10

.~A .399 .3591 . 3990

Tot .408 .3592 . 4000

So P(A|B)=9/408=3/136

P(~A|~B)=3591/3592

As before.

Step-by-step explanation: its were the answer is

5 0

3 years ago

Assume that you have a sample of n 1 equals 6, with the sample mean Upper X overbar 1 equals 50, and a sample standard deviati

tigry1 [53]

Answer:

$t=\frac{(50 -38)-(0)}{7.46\sqrt{\frac{1}{6}+\frac{1}{5}}}=2.656$

$df=6+5-2=9$

$p_v =P(t_{9}>2.656) =0.0131$

Since the p value is higher than the significance level given of 0.01 we don't have enough evidence to conclude that the true mean for group 1 is significantly higher thn the true mean for the group 2.

Step-by-step explanation:

Data given

$n_1 =6$ represent the sample size for group 1

$n_2 =5$ represent the sample size for group 2

$\bar X_1 =50$ represent the sample mean for the group 1

$\bar X_2 =38$ represent the sample mean for the group 2

$s_1=7$ represent the sample standard deviation for group 1

$s_2=8$ represent the sample standard deviation for group 2

System of hypothesis

The system of hypothesis on this case are:

Null hypothesis: $\mu_1 \leq \mu_2$

Alternative hypothesis: $\mu_1 > \mu_2$

We are assuming that the population variances for each group are the same

$\sigma^2_1 =\sigma^2_2 =\sigma^2$

The statistic for this case is given by:

$t=\frac{(\bar X_1 -\bar X_2)-(\mu_{1}-\mu_2)}{S_p\sqrt{\frac{1}{n_1}+\frac{1}{n_2}}}$

The pooled variance is:

$S^2_p =\frac{(n_1-1)S^2_1 +(n_2 -1)S^2_2}{n_1 +n_2 -2}$

We can find the pooled variance:

$S^2_p =\frac{(6-1)(7)^2 +(5 -1)(8)^2}{6 +5 -2}=55.67$

And the pooled deviation is:

$S_p=7.46$

The statistic is given by:

$t=\frac{(50 -38)-(0)}{7.46\sqrt{\frac{1}{6}+\frac{1}{5}}}=2.656$

The degrees of freedom are given by:

$df=6+5-2=9$

The p value is given by:

$p_v =P(t_{9}>2.656) =0.0131$

4 0

3 years ago

Nothing at all nothing

Dmitriy789 [7]

Answer would be #9 .hourses

5 0

3 years ago

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The sail of a boat is in the shape of a right triangle, as shown below:

dolphi86 [110]

Answer: Choice C
7 divided by cosec 50 degrees

=====================================

Explanation:

Abbreviations:
sec = secant
cot = cotangent
cosec = cosecant (csc is also a widely used abbreviation)

-----------------

Let the horizontal leg be x

This leg is opposite the angle 50 degrees. The hypotenuse is 7

Opposite = x
Hypotenuse = 7

We'll either use the sine rule or the cosecant (csc) rule
sine = opposite/hypotenuse
cosecant = hypotenuse/opposite

Since "sine" is nowhere to be found in the answer choices, we'll use the cosecant rule

-----------

cosecant = hypotenuse/opposite
csc(angle) = hypotenuse/opposite
csc(50) = 7/x
x*csc(50) = 7
x = 7/csc(50)

This is why the answer is choice C

6 0

3 years ago

Read 2 more answers