All categories

3 years ago

Solve by substitution x-2y= -25 and 3x-y=0

Mathematics

1 answer:

andreev551 [17]3 years ago

5 0

Answer:

x=5 and y=15

Step-by-step explanation:

x−2y=−25

x−2y+2y=−25+2y(Add 2y to both sides)

x=2y−25

Step: Substitute2y−25forxin3x−y=0:

3x−y=0

3(2y−25)−y=0

5y−75=0(Simplify both sides of the equation)

5y−75+75=0+75(Add 75 to both sides)

5y=75

(Divide both sides by 5)

y=15

Step: Substitute 15fory in x=2y−25:

x=2y−25

x=(2)(15)−25

x=5(Simplify both sides of the equation)

You might be interested in

Find out the number of combinations and the number of permutations for 8 objects taken 6 at a time. Express your answer in exact

umka2103 [35]

Solution:

The permutation formula is expressed as

$\begin{gathered} P^n_r=\frac{n!}{(n-r)!} \\ \end{gathered}$

The combination formula is expressed as

$\begin{gathered} C^n_r=\frac{n!}{(n-r)!r!} \\ \\ \end{gathered}$

where

$\begin{gathered} n\Rightarrow total\text{ number of objects} \\ r\Rightarrow number\text{ of object selected} \end{gathered}$

Given that 6 objects are taken at a time from 8, this implies that

$\begin{gathered} n=8 \\ r=6 \end{gathered}$

Thus,

Number of permuations:

$\begin{gathered} P^8_6=\frac{8!}{(8-6)!} \\ =\frac{8!}{2!}=\frac{8\times7\times6\times5\times4\times3\times2!}{2!} \\ 2!\text{ cancel out, thus we have} \\ \begin{equation*} 8\times7\times6\times5\times4\times3 \end{equation*} \\ \Rightarrow P_6^8=20160 \end{gathered}$

Number of combinations:

$\begin{gathered} C^8_6=\frac{8!}{(8-6)!6!} \\ =\frac{8!}{2!\times6!}=\frac{8\times7\times6!}{6!\times2\times1} \\ 6!\text{ cancel out, thus we have} \\ \frac{8\times7}{2} \\ \Rightarrow C_6^8=28 \end{gathered}$

Hence, there are 28 combinations and 20160 permutations.

7 0

1 year ago

Gabrielle's age is two times Mikhail's age. The sum of their ages is 81. What is Mikhail's age?

Darya [45]

Answer:

Step-by-step explanation:

Let g be Gabrielle's age and m be Mikhail's age.

We can turn the statements the problem gives us into mathematical expressions to help us solve.

Gabrielle's age is two times Mikhail's age:

g = 2m

The sum of their ages is 81:

g + m = 81

This gives us a system of equations that will allow us to solve for Gabrielle's age.

g + m = 81

(2m) + m = 81

3m = 81

m = $\frac{81}{3}$

m = 27

If we need to solve for Gabrielle's age, we can do the following.

g = 2m

2(27) = g

54 = g

g = 54

Mikhail's age is 27.

Gabrielle's age is 54.

8 0

2 years ago

Read 2 more answers

Do oddsmakers believe that teams who play at home will have home field advantage? Specifically, do oddsmakers give higher point

anygoal [31]

Complete question is;

Do oddsmakers believe that teams who play at home will have home field advantage? Specifically, do oddsmakers give higher point spreads when the favored team plays home games as compared to when the favored team plays away games?

Two samples were randomly selected from three complete National Football League seasons (1989, 1990, and 1991). The first sample consisted of 50 games, where the favored team played in a home game, while the second sample consisted of 50 games, where the favored team played in an away game. The oddsmakers’ point spreads (which are the number of points by which the favored team is predicted to beat the weaker team) were then collected.

If µ1 and µ2 represent the mean point spread for home games and away games, respectively, which of the following is the appropriate.

A) H0: μ1 - μ2 = 0

Ha: μ1 - μ2 < 0

B) H0: μ1 - μ2 = 0

Ha: μ1 < μ2

C) H0: μ1 - μ2 > 0

Ha: μ1 - μ2 = 0

D) H0: μ1 - μ2 = 0

Ha: μ1 - μ2 > 0

E) None of the above

Answer:

D) H0: μ1 - μ2 = 0

Ha: μ1 - μ2 > 0

Step-by-step explanation:

We want to find out if oddsmakers give higher point spreads when the favored team plays home games as compared to when the favored team plays away games.

Now, since µ1 and µ2 represent the mean point spread for home games and away games, respectively;

It means we want to find out if µ1 > µ2 as the alternative hypothesis.

Thus, alternative hypothesis is;

Ha: µ1 - µ2 > 0

Meanwhile null hypothesis assumes that equal point spreads are given when the favored team plays home games as well as when the favored team plays away games.

Thus, null hypothesis is;

H0: μ1 - μ2 = 0

The only correct option is D.

8 0

2 years ago

What is the value of x in this equation? x - 1/2 = 3 1/6

Ludmilka [50]

Answer:

x= 3 2/3

Step-by-step explanation:

6 0

3 years ago

Fourteen less than three fourths of a number is negative eight. Find the number

Lapatulllka [165]

The word "is" in this kind of problem typically means "=", so we know that something =-8. Since we're finding the number, we should start with the closest thing in the phrase given to that number. In this case, it's 3/4x. Finally, since we have the "14 less than", we need to add that in. Your answer is:

3/4x-14=-8. Now we can just solve!
+14 +14

3/4x=6.
*4/3 *4/3

x=8.


Don't forget to rate this answer the Brainliest!

8 0

3 years ago