Question

6. Using the elimination method, solve each of the following pairs of simultaneous equations, (a) 4x - y - 7 = 0 4x + 3y - 11 = 0 ​

Answer 1

Answer:

3x+2y=7 ----- (1)

4x−3y=−2----- (2)

Multiply equation (1) by 3 and equation (2) by 2, then add

9x+6y=21

8x−6y=−4

______________

17x=17

x=  

17

17

​

=1

Put the value of x in equation (1), we get

3x+2y=7

3(1)+2y=7

2y=7−3

2y=4

y=  

2

4

​

=2

Therefore the solution is (1, 2)

Answer 2

Answer:

4x - y - 7 = 0

4x - y = 7_______(1)

4x + 3y - 11 = 0

4x + 3y = 11______(2)

substracting equation 1 from 2

4x + 3y = 11

-. 4x - y = 7

(-). (+). (-)

____________________

4y = 4

:: y = 4/4

:: y = 1

substituting y = 1 in equation 1,

4x - y = 7

:: 4x - 1 = 7

:: 4x = 7 + 1

:: 4x = 8

:: x = 8/4

:: x = 2

Step-by-step explanation:

The solution of given equation is ( x,y) = ( 2,1 ).