What would be 2 + 7x + 3 − 5x − 1 = _____

NEED RN, WORTH 20! What is the value of x?

max2010maxim [7]

Answer:

$x = 5.625$

Step-by-step explanation:

Step 1: Make an expression

$\frac{3}{4} = \frac{x}{7.5}$

Step 2: Cross Multiply

$\frac{3}{4} = \frac{x}{7.5}$

$4 * x = 7.5 * 3$

$4x = 22.5$

Step 3: Divide both sides by 4

$4x / 4 = 22.5 / 4$

$x = 5.625$

Answer: $x = 5.625$

5 0

2 years ago

Write a proportion to find how many points x a student needs to score on a test worth 50 points to get a test score of 78%.

olganol [36]

The answer is: "39 points" .
_______________________________________________________
Explanation:
_______________________________________________________
" x/ 50 = 78/100 " ; in which "x" equals the number of points needed.

_______________________________________________________

To solve for "x" ;
_______________________________________________________

Look at the denominators: 50 * (what value?) = 100.

→ "100 ÷ 50 = 2" .

→ So; "50 * 2 = 100" ;

So, let us look at the numerators:

x * 2 = 78 ;

↔ 2x = 72 ;

Divide each side of the equation by "2" ; to isolate "x" on one side of the equation ; and to solve for "x" ;
_____________________________________________
→ 78 ÷ 2 = 39 ;

The answer is: "39 points" .
_____________________________________________

4 0

2 years ago

PLS HELP ASAP STUMPED ON THIS ONE!!!!!!! ?/? ÷ 5 = 12/50

Svet_ta [14]

Answer:

6/5 or 1.2

Step-by-step explanation:

you can solve with an equation:

x : 5 = 12 : 50

x = 5 * 12 : 50

x = 6/5 (or 1.2)

or you can solve with an expression

12/50 * 5 = 6/5 (or 1.2)

8 0

2 years ago

If a test of H subscript 0 colon space mu subscript D equals 0 space v s. space H subscript a colon space space mu subscript D g

lara [203]

Answer:

$p_v =P(t_{(n-1)}>t_{calculated}) =0.0601$

The p value on this case is given by the problem.

If we compare the p value with a significance level assumed $\alpha=0.05$ , we see that $p_v > \alpha$ and we can conclude that we FAIL to reject the null hypothesis that the difference mean between after and before is less or equal than 0.

Step-by-step explanation:

A paired t-test is used to compare two population means where you have two samples in which observations in one sample can be paired with observations in the other sample. For example if we have Before-and-after observations (This problem) we can use it.

Let put some notation

x=test value before , y = test value after

The system of hypothesis for this case are:

Null hypothesis: $\mu_y- \mu_x \leq 0$

Alternative hypothesis: $\mu_y -\mu_x >0$

The first step is calculate the difference $d_i=y_i-x_i$

The second step is calculate the mean difference

$\bar d= \frac{\sum_{i=1}^n d_i}{n}$

The third step would be calculate the standard deviation for the differences, and we got:

$s_d =\frac{\sum_{i=1}^n (d_i -\bar d)^2}{n-1}$

The 4 step is calculate the statistic given by :

$t=\frac{\bar d -0}{\frac{s_d}{\sqrt{n}}}=t_{calculated}$

The next step is calculate the degrees of freedom given by:

$df=n-1$

Now we can calculate the p value, since we have a right tailed test the p value is given by:

$p_v =P(t_{(n-1)}>t_{calculated}) =0.0601$

The p value on this case is given by the problem.

If we compare the p value with a significance level assumed $\alpha=0.05$ , we see that $p_v > \alpha$ and we can conclude that we FAIL to reject the null hypothesis that the difference mean between after and before is less or equal than 0.

4 0

3 years ago

Six cell phones weigh 46.2 ounces. Fourteen cell phones weigh 107.8 ounces. What is the unit rate or constant of proportionality

iris [78.8K]

Answer:

Well first we must see if they are proportional. 

 

46.2/6 = 10.7.8/14 

7.7 = 7.7 

 

They are proportional. The rate of proportion is 7.7 ounces per cellphone. Hope this helps! 

Step-by-step explanation:

8 0

2 years ago

What would be 2 + 7x + 3 − 5x − 1 = ______ plz help