It's in the pic plz help

for the equation 2x(3x+5)+3(3x+5)=ax^2+bx+c , if this equation is true for all values of x,what is the value of b if a,b,and c a

guapka [62]

Answer:

b=19

Step-by-step explanation:

2x(3x+5)+3(3x+5)=ax2 +bx+c

by expansion,

6x2 +10x +9x+15=6x2 +19x +15

6 0

3 years ago

The officer stepped off 20 paces from E to G. If his pace is 2 1/2 feet long. How wide was the river?

Sergeeva-Olga [200]

Answer:

The wide of river is $50\ ft$

Step-by-step explanation:

In this problem we know that

Triangles DEG and DEF are congruent by ASA (Angle-Side-Angle) Congruence

therefore

EG=EF

$EG=20*(2\frac{1}{2})=20*\frac{5}{2}=50\ ft$

8 0

3 years ago

A researcher wants to test whether a certain sound will make rats do worse on learning tasks. It is known that an ordinary rat c

AveGali [126]

Answer:

So we reject the null hypothesis and accept the alternate hypothesis that rats learn slower with sound.

Step-by-step explanation:

In this data we have

Mean= u = 18

X= 38

Standard deviation = s= 6

1) We formulate the null and alternate hypothesis as

H0: u = 18 against Ha : u > 18 One tailed test .

2) The significance level alpha = ∝= 0.05 and Z alpha has a value ± 1.645 for one tailed test.

3)The test statistics used is

Z= X- u / s

z= 38-18/6= 3.333

4) The calculated value of z = 3.33 is greater than the z∝ = 1.645

5) So we reject the null hypothesis and accept the alternate hypothesis that rats learn slower with sound.

First we set the criteria for determining the true of value of the variable. That whether the rats learn in less or more than 18 trials.

Then we find the value of z for the given significance value given and the test about to be checked.

Then the test statistic is determined and calculated.

Then both value of z and z alpha re compared. If the test statistics falls in the rejection region reject the null hypothesis and conclude alternate hypothesis is true.

The figure shows that the calulated z value lies outside the given z values

4 0

2 years ago

In a study of cereal leaf beetle damage to oats, researchers measured the number of beetle larvae per stem in small plots of oat

PSYCHO15rus [73]

Answer:

At 0.05 level of significance, there is no difference in the mean number of larvae per stem. This supports the scientist's claim.

(d) H0: MeanMalathion - MeanNoMalathion equals 0

H1: MeanMalathion - MeanNoMalathion not equals 0

Step-by-step explanation:

Test statistic (t) = (mean 1 - mean 2) ÷ sqrt[pooled variance (1/n1 + 1/n2)]

Let the difference between the two means be x and the pooled variance be y

n1 = 5, n2 = 12

t = x ÷ sqrt[y(1/5 + 1/12)] = x ÷ sqrt(0.283y) = x ÷ 0.532√y = 1.88x/√y

Assuming the ratio of x to √y is 0.5

t = 1.88×0.5 = 0.94

n1 + n2 = 5 + 12 = 17

degree of freedom = n1 + n2 - 2 = 17 - 2 = 15

significance level = 0.05 = 5%

critical value corresponding to 15 degrees of freedom and 5% confidence interval is 2.131

The test is a two-tailed test because the alternate hypothesis is expressed using not equal to.

The region of no rejection of the null hypothesis lies between -2.131 and 2.131

Conclusion

Fail to reject the null hypothesis because the test statistic 0.94 falls within the region bounded by the critical values.

The scientist's claim is right.

A null hypothesis is a statement from a population parameter which is either rejected or accepted (fail to reject) upon testing. It is expressed using the equality sign.

An alternate hypothesis is also a statement from a population parameter which negates the null hypothesis and is accepted if the null hypothesis is rejected. It is expressed using any of the inequality signs.

3 0

3 years ago

A pitcher has 16 cups of water in it. During the day, Aditi drank 5⁄2 cups, Kavitha drank 15⁄4 cups, and Rahul drank 33⁄8 cups.

iragen [17]

Answer:

5/2 = 2 1/2

15/4 = 3 3/4

33 /8 = 4 1/8

Step-by-step explanation:

5/2 2 goes into 5 2 times with 1 left over = 2 1/2

15 /4 4 goes into 15 3 times with 3 left over 3 3/4

33/8 8 goes into 33 4 times with 1 left over 4 1/8

5 0

3 years ago