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3 years ago

1. The difference of two numbers is 3, and the sum of three times the larger one and

Mathematics

1 answer:

vlada-n [284]3 years ago

5 0

Answer: 25 and 22

Step-by-step explanation:

Since one number is 3 bigger than the other, we can call them x, and x-3.

Then we know that the sum of 3 times x and 2 times (x-3) is equal to 19, so we can make the equation

3x+2(x-3)=19

Simplifying would get you

3x+2x-6=19

adding the x's and adding six to both sides of the equations gets you

5x = 25

divide by 5 and

x=5

Put those numbers back into your previous labels for them, x and x-3, and you get 5 and 2

Hope this helps

You might be interested in

What notation is used to represent the distance from point A to B

borishaifa [10]

Answer:

Absolute Value

Step-by-step explanation:

Absolute Value is very useful in finding the distance between two points on the number line. The distance between any two points a and b in the number line is

|a-b| or |b-a|.

7 0

2 years ago

What is the equation, in slope-intercept form, for the line that passes through the point (2, −3) and is perpendicular to the li

diamong [38]

Answer:

The equation is;

y = (-x-23)/25

Step-by-step explanation:

The equation of a straight line can be given as y = mx + b

where m is the slope and b is the y-intercept

for y = 25x + 4

m is 25

Now, we need the slope of a line perpendicular to this,

If two lines are perpendicular, the result of the product of their slopes is -1

m1 * m2 = -1

25 * m2 = -1

m2 = -1/25

Mathematically, we have the slope in the point slope form as ;

y+3 = -1/25 (x - 2)

y = -x/25 + 2/25

y = -x/25 + 2/25 - 3

y = -x/25 -73/25

6 0

2 years ago

5) In a certain supermarket, a sample of 60 customers who used a self-service checkout lane averaged 5.2 minutes of checkout tim

Ne4ueva [31]

Answer:

$\S^2_p =\frac{(60-1)(3.1)^2 +(72 -1)(2.8)^2}{60 +72 -2}=8.643$

$S_p=2.940$

$t=\frac{(5.2 -6.1)-(0)}{2.940\sqrt{\frac{1}{60}+\frac{1}{72}}}=-1.751$

$df=60+72-2=130$

$p_v =P(t_{130}$

Assuming a significance level of $\alpha=0.05$ we have that the p value is lower than this significance level so then we can conclude that the mean for checkout time is significantly less for people who use the self-service lane

Step-by-step explanation:

Data given

Our notation on this case :

$n_1 =60$ represent the sample size for people who used a self service

$n_2 =72$ represent the sample size for people who used a cashier

$\bar X_1 =5.2$ represent the sample mean for people who used a self service

$\bar X_2 =6.1$ represent the sample mean people who used a cashier

$s_1=3.1$ represent the sample standard deviation for people who used a self service

$s_2=2.8$ represent the sample standard deviation for people who used a cashier

Assumptions

When we have two independent samples from two normal distributions with equal variances we are assuming that

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

The statistic is given by:

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

And t follows a t distribution with $n_1+n_2 -2$ degrees of freedom and the pooled variance $S^2_p$ is given by this formula:

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

System of hypothesis

Null hypothesis: $\mu_1 \geq \mu_2$

Alternative hypothesis: $\mu_1 < \mu_2$

This system is equivalent to:

Null hypothesis: $\mu_1 - \mu_2 \geq 0$

Alternative hypothesis: $\mu_1 -\mu_2 < 0$

We can find the pooled variance:

$\S^2_p =\frac{(60-1)(3.1)^2 +(72 -1)(2.8)^2}{60 +72 -2}=8.643$

And the deviation would be just the square root of the variance:

$S_p=2.940$

The statistic is given by:

$t=\frac{(5.2 -6.1)-(0)}{2.940\sqrt{\frac{1}{60}+\frac{1}{72}}}=-1.751$

The degrees of freedom are given by:

$df=60+72-2=130$

And now we can calculate the p value with:

$p_v =P(t_{130}$

5 0

3 years ago

Not really sure how to do this with a negative number

Oksi-84 [34.3K]

1/2*(-1/7) = - (1*1)/(2*7)= - 1/14

(+)*(-) = (-)

Answer : - 1/14

4 0

3 years ago

Read 2 more answers

Help help help help help

Mkey [24]

Answer:

x = 42

Step-by-step explanation:

The marked angles are supplementary, so their sum is 180°.

(2x +8) +(2x +4) = 180

4x +12 = 180 . . . . . . . . . simplify

x +3 = 45 . . . . . . . divide by 4 (because we can)

x = 42 . . . . . . subtract 3

_____

<em>Additional comment</em>

A "two-step" linear equation like this one is usually solved by subtracting the unwanted constant, then dividing by the coefficient of the variable. Here, we have done those steps in reverse order. This makes the numbers smaller and eliminates the coefficient of the variable. Sometimes I find it easier to solve the equation this way.

5 0

2 years ago