Mathematics
Grade-8
Easy
Question
Solve the following using the substitution method and find the value of x and y:
x – 5y = 12
x – y = 4
- 2, -2
- 3, -3
- 4, -4
- 1, -4
Hint:
The substitution method is the algebraic method to solve simultaneous linear equations. , in this method, the value of one variable from one equation is substituted in the other equation. In this way, a pair of the linear equation gets transformed into one linear equation with only one variable, which can then easily be solved.
The correct answer is: 2, -2
In this method, the elimination of the variable can be performed by substituting the value of another variable in an equation. Hence, this method is called the elimination by substitution method.
x – 5y = 12 and x – y = 4
Given:
x – 5y = 12 … (1)
x – y = 4 …(2)
The equation (2) can be written as
x = 4 + y … (3)
Now, in equation (1) eliminate the variable x by substituting the value of x in terms of y in equation (1).
Hence, equation (1) becomes
4 + y - 5y = 12
-4y = 8
y = -2
Hence, the value of y is -2.
Now, substituting y= -2 in the equation (3), we get
x = 4 + (-2)
x = 2
Therefore, the value of x is 2.
Hence, the solution for the system of linear equations is:
x = 2 and y= -2
To check whether the obtained solution is correct or not, substitute the values of x and y in any of the given equations.
Verification:
Use Equation (2) to verify the solution
x – y = 4
Now, substitute x= 2 and y= -2
2 - (-2) = 4
4 = 4
Here, L.H.S = R.H.S
Thus, the obtained solution is correct.
Related Questions to study
Mathematics
Solve the following using the substitution method and find the value of x and y:
-5x - 4y = 32
2y = -6
Solve the following using the substitution method and find the value of x and y:
-5x - 4y = 32
2y = -6
MathematicsGrade-8
Mathematics
Solve the following using the substitution method and find the value of x and y:
-3y = 12
5x + 5y = -45
Solve the following using the substitution method and find the value of x and y:
-3y = 12
5x + 5y = -45
MathematicsGrade-8
Mathematics
Solve the following using the substitution method and find the value of x and y:
-2y = 10
-2x + y = -11
Solve the following using the substitution method and find the value of x and y:
-2y = 10
-2x + y = -11
MathematicsGrade-8
Mathematics
Solve the following using the substitution method and find the value of x and y:
-4y = -4
-5x = 15
Solve the following using the substitution method and find the value of x and y:
-4y = -4
-5x = 15
MathematicsGrade-8
Mathematics
Solve the following using the substitution method and find the value of x and y:
x – 3y = 1
-3x – y = -13
Solve the following using the substitution method and find the value of x and y:
x – 3y = 1
-3x – y = -13
MathematicsGrade-8
Mathematics
Solve the following using the substitution method and find the value of x and y:
-x + 2y = 9
-5x – 4y = -11
Solve the following using the substitution method and find the value of x and y:
-x + 2y = 9
-5x – 4y = -11
MathematicsGrade-8
Mathematics
Solve the following using the substitution method and find the value of x and y:
4x – 4y = 32
4x – 2y = 14
Solve the following using the substitution method and find the value of x and y:
4x – 4y = 32
4x – 2y = 14
MathematicsGrade-8
Mathematics
Solve the following using the substitution method and find the value of x and y:
-5x + 3y = -22
-5x + y = -24
Solve the following using the substitution method and find the value of x and y:
-5x + 3y = -22
-5x + y = -24
MathematicsGrade-8
Mathematics
Solve the following using the substitution method and find the value of x and y:
5x = 10
-x + y = -2
Solve the following using the substitution method and find the value of x and y:
5x = 10
-x + y = -2
MathematicsGrade-8
Mathematics
Solve the following using the substitution method and find the value of x and y:
5x – 2y = -4
-5x + 4y = 8
Solve the following using the substitution method and find the value of x and y:
5x – 2y = -4
-5x + 4y = 8
MathematicsGrade-8
Mathematics
Solve the following using the substitution method and find the value of x and y:
-x + 2y = 3
3y = -3
Solve the following using the substitution method and find the value of x and y:
-x + 2y = 3
3y = -3
MathematicsGrade-8
Mathematics
Solve the following using the substitution method and find the value of x and y:
-2x - 2y = -14
-5x – y = -23
Solve the following using the substitution method and find the value of x and y:
-2x - 2y = -14
-5x – y = -23
MathematicsGrade-8
Mathematics
Solve the following using the substitution method and find the value of x and y:
- x – 4y =16
- 5x - 5y = 5
Solve the following using the substitution method and find the value of x and y:
- x – 4y =16
- 5x - 5y = 5
MathematicsGrade-8
Mathematics
Solve the following using the substitution method and find the value of x and y:
-5x = 25
3x + 5y = -35
Solve the following using the substitution method and find the value of x and y:
-5x = 25
3x + 5y = -35
MathematicsGrade-8
Mathematics
Solve the following using the substitution method and find the value of x and y:
5x + y = -10
2x + 5y = 19
Solve the following using the substitution method and find the value of x and y:
5x + y = -10
2x + 5y = 19
MathematicsGrade-8