Answer:
The correct solutions are (6, -2).
Step-by-step explanation:
For the first equation, rearrange to make x the subject.
3x + 4y = 10
Divide the whole equation by 3 to isolate x:
Now substitute this into the second equation:
Subtract 20 from both sides:
20 - 10y = 40
20 - 10y - 20 = 40 - 20
-10y = 20
Divide both sides by 2:
-10y ÷ 10 = 20 ÷ 10
-y = 2 ∴ y = -2
Plug this value back into the first equation:
3x + 4y = 10
3x + 4(-2) = 10
3x + (-8) = 10
3x - 8 = 10
Add 8 to both sides:
3x - 8 + 8 = 10 + 8
3x = 18
Divide both sides by 3:
3x ÷ 3 = 18 ÷ 3
x = 6
Therefore, the correct solutions are (6, -2).
Hope this helps!
Answer:
a. x=9, b. x=6
Step-by-step explanation:
In a the triangle is cut in half. the sides are equal even though the triangle is slanted.
In b the triangles are similar if you flip the big one. Since the smaller triangle is smaller it is a reduced form of the larger one.
Use the free service at Random.Org to generate a true random sample from the number of persons in your class. The attachment shows a random sample from the range 1–35. Use the numbers generated to select persons from the class with the same indentifying number.
Answer:
values ranging fromminus infinity to negative 20
Step-by-step explanation:
we write the inequality associated with the text in terms of the unknown number "x" as:
then, we solve for "x" by adding 2 to both sides, and then isolating "x" on the left as shown below:
then, the range of x-values is from minus infinity to negative 20
Answer:
The 90% for the average weights of men is between 137.24 lb and 185.76 lb.
Step-by-step explanation:
We have the standard deviation for the sample, so we use the t-distribution to solve this question.
The first step to solve this problem is finding how many degrees of freedom, we have. This is the sample size subtracted by 1. So
df = 14 - 1 = 14
90% confidence interval
Now, we have to find a value of T, which is found looking at the t table, with 14 degrees of freedom(y-axis) and a confidence level of . So we have T = 1.7709
The margin of error is:
M = T*s = 1.7709*13.7 = 24.26
In which s is the standard deviation of the sample.
The lower end of the interval is the sample mean subtracted by M. So it is 161.5 - 24.26 = 137.24 lb
The upper end of the interval is the sample mean added to M. So it is 161.5 + 24.26 = 185.76 lb
The 90% for the average weights of men is between 137.24 lb and 185.76 lb.
O 5x - 32
0 21x + 23
0 5x + 23
O 5x - 17
Answer:
5x+23
Step-by-step explanation:
3(x+1) - 4(2x-5) + 10x
3x+3 - 8x+20 + 10x
(3x-8x+10x = 5x)
(3+20 = 23)
Therefore, answer is 5x-23. :)