Question

10 sum of substitute method​

Answer 1

Answer:

Substitution Method Questions 10

Question 10 :

Solve the following equations by substitution method

y = −2 and 4x − 3y = 18

Solution :

y = −2 -------(1)

4x − 3y = 18 -------(2)

Apply y = -2 in the second equation

4x − 3(-2) = 18

4x + 6 = 18

Subtract by 6 on both sides

4x + 6 - 6 = 18 - 6

4x = 12

Divide by 1 on both sides

4x/4 = 12/4

x = 3

Hence the solution is x = 3 and y = -2. Substitution method questions 10

More practice questions

Question 1 :

Solve the following equations by substitution method

5 x - 3 y - 8 = 0 and 2x - 3 y - 5 = 0

Solution

Question 2 :

Solve the following equations using substitution method

5x - 3y - 8 = 0 and 2x - 3y - 5 = 0

Solution

Question 3 :

Solve the following equations by substitution method

y = 6x - 11 and -2x - 3y = -7

Solution

Question 4 :

Solve the following equations by substitution method

2x − 3y = −1 and y = x − 1

Solution

Question 5 :

Solve the following equations by substitution method

y = −3x + 5 and 5x − 4y = −3

Solution

Question 6 :

Solve the following equations by substitution method

−3x − 3y = 3 and y = −5x − 17

Solution

Question 7 :

Solve the following equations by substitution method

y = 5x − 7 and −3x − 2y = −12

Solution

Question 8 :

Solve the following equations by substitution method

−4x + y = 6 and −5x − y = 21

Solution

Question 9 :

Solve the following equations by substitution method

2x + y = 20 and 6x − 5y = 12

Solution

Question 10 :

Solve the following equations by substitution method

y = −2 and 4x − 3y = 18

Solution

Answer 2

Question 1-

Solve the pair of linear equations: 4x + 6y = 10 and 2x – 3y = 8 using Substitution method.

Solution:

4x + 6y = 10 ………….(i)

2x – 3y = 8 ……………(ii)

Finding the value of y in terms of x from equation (1), we get-

4x + 6y = 10

⇒ 6y = 10 – 4x

⇒ y = 10−4x6 ……………….(3)

Using this method, substituting the value of y in equation (2), we get-

2x–3(10 − 4x6) = 10

⇒ 2x – 5 + 2x = 10

⇒ 4x = 15

⇒ x = 154

Finding the value of y, substitute the value of x in equation (3), we get-

y = 10 − 4∗(154)6

⇒ y = 10 − 156

⇒ y = −56

Hence the value of y is –56 and x is 154.

Question 2-

Solve by substitution

2x+5y =12

4x−y=2

SOLUTION:

Step 1: Solve one of the equations for either x = or y =. Since the coefficient of y in equation 2 is -1, it is easiest to solve for y in equation 2.

4x−y−yy=2=2−4x=4x−2

Step 2: Substitute the solution from step 1 into the second equation.

2x+5y2x+5(4x−2)=12=12

Step 3: Solve this new equation ( for x ).

2x+5(4x−2)2x+2x+20x−1022xx=12=12=22=1

Step 4: Solve for the second variable

yyy=4x−2=4⋅x−2=2

The solution is: (x,y)=(1,2)

Hope it helps you ✌️