Maths-

General

Easy

Question

According to the system of equations above, what is the value of X ?

- 6
- 8
- 13
- 15

Hint:

**Hint:**

We are given two linear equations in two variables. To find the value of X , we need to solve them. Try to eliminate one variable in any one of the equations with the help of other equation. As we need to find the value of X , we try to find the value of Y in terms of X from one equation. Then put that value of Y in the other equation to get a linear equation in one variable, that is X, . This can be solved easily to get the required value.

## The correct answer is: 13

### The given equations are,

. . .(1)

. . . (2)

From equation (1), we have

Using this value of *y *in equation (2), we get

The required value of x=13.

The correct option is C.

**Note:**

Here we find the value of *y* from equation (1) and use it in equation (2).

We could do it the other way and receive the same answer, that is, if we find the value of y from equation (2) and use it in equation (1) to find x, we get the same value of x as found in the solution above.

Students are encouraged to try this method too.

### Related Questions to study

Maths-

Maths-General

Maths-

The scatterplot above shows the number of registered voters, , x and the number of people who voted in

the last election, y , for seven districts in a town. A line of best fit for the data is also shown. Which of the following could be the equation of the line of best fit?

The scatterplot above shows the number of registered voters, , x and the number of people who voted in

the last election, y , for seven districts in a town. A line of best fit for the data is also shown. Which of the following could be the equation of the line of best fit?

Maths-General

Maths-

### The relationship between x and y can be written as y = mx , where m is a constant. If y = 17 when x =a , what is the value of y when x = 2a ?

### The relationship between x and y can be written as y = mx , where m is a constant. If y = 17 when x =a , what is the value of y when x = 2a ?

Maths-General

Maths-

### 700 , 1200 ,1600 , 2000 , x

If the mean of the five numbers above is 1600 , what is the value of x?

### 700 , 1200 ,1600 , 2000 , x

If the mean of the five numbers above is 1600 , what is the value of x?

Maths-General

Maths-

Some values of x and their corresponding values of y are shown in the table above, where a is a constant. If there is a linear relationship between x and y, which of the following equations represents the relationship?

Some values of x and their corresponding values of y are shown in the table above, where a is a constant. If there is a linear relationship between x and y, which of the following equations represents the relationship?

Maths-General

Maths-

In the triangle above, a = 34. What is the value of b + c ?

In the triangle above, a = 34. What is the value of b + c ?

Maths-General

Maths-

### Lynne has $8.00 to spend on apples and oranges. Apples cost $0.65 each, and oranges cost $0.75 each. If there is no tax on this purchase and she buys 5 apples, what is the maximum number of whole oranges she can buy?

### Lynne has $8.00 to spend on apples and oranges. Apples cost $0.65 each, and oranges cost $0.75 each. If there is no tax on this purchase and she buys 5 apples, what is the maximum number of whole oranges she can buy?

Maths-General

Maths-

### The first year Eleanor organized a fund-raising event, she invited 30 people. For each of the next 5 years, she invited double the number of people she had invited the previous year. If is the number of people invited to the fund-raiser years after Eleanor began organizing the event, which of the following statements best describes the function ?

### The first year Eleanor organized a fund-raising event, she invited 30 people. For each of the next 5 years, she invited double the number of people she had invited the previous year. If is the number of people invited to the fund-raiser years after Eleanor began organizing the event, which of the following statements best describes the function ?

Maths-General

Maths-

Clayton will mix X milliliters of a 10 % by mass saline solution with y milliliters of a by mass saline solution in order to create an 18% by mass saline solution. The equation above represents this situation. If Clayton uses 100 milliliters of the 20% by mass saline solution, how many milliliters of the 10% by mass saline solution must he use?

Clayton will mix X milliliters of a 10 % by mass saline solution with y milliliters of a by mass saline solution in order to create an 18% by mass saline solution. The equation above represents this situation. If Clayton uses 100 milliliters of the 20% by mass saline solution, how many milliliters of the 10% by mass saline solution must he use?

Maths-General

Maths-

### The maximum value of a data set consisting of 25 positive integers is 84 . A new data set consisting of 26 positive integers is created by including 96 in the original data set. Which of the following measures must be 12 greater for the new data set than for the original data set?

### The maximum value of a data set consisting of 25 positive integers is 84 . A new data set consisting of 26 positive integers is created by including 96 in the original data set. Which of the following measures must be 12 greater for the new data set than for the original data set?

Maths-General

General

In the equation above, a is a constant. The graph of the equation in the x y - plane is a parabola. Which of the following is true about the parabola?

In the equation above, a is a constant. The graph of the equation in the x y - plane is a parabola. Which of the following is true about the parabola?

GeneralGeneral

Maths-

The table above shows the results of a survey in which tablet users were asked how often they would watch video advertisements in order to access streaming content for free. Based on the table, which of the following is closest to the probability that a tablet user answered "Always," given that the tablet user did not answer "Never"?

The table above shows the results of a survey in which tablet users were asked how often they would watch video advertisements in order to access streaming content for free. Based on the table, which of the following is closest to the probability that a tablet user answered "Always," given that the tablet user did not answer "Never"?

Maths-General

Maths-

### Find the smallest square number by which 9408 must be divided , so that it becomes a perfect square.

### Find the smallest square number by which 9408 must be divided , so that it becomes a perfect square.

Maths-General

Maths-

### The volume of a sphere is given by the formula , where r is the radius of the sphere. Which of the following gives the radius of the sphere in terms of the volume of the sphere?

### The volume of a sphere is given by the formula , where r is the radius of the sphere. Which of the following gives the radius of the sphere in terms of the volume of the sphere?

Maths-General

Maths-

### Evaluate a)

### Evaluate a)

Maths-General