Question

29
(iii) 4x – 3y = 8,6x - y =
3.elimination method​

Answer 1

Question

4x - 3y = 8

6x - y = 3

find value of x and y by elimination method .

Solution :-

Given

4x - 3y = 8 -----------(1)

6x - y = 3 ------------(2)

By elimination method

Multiply by 3 in equation (1) and 2 in equation (2) =>

12x - 9y = 24 -----------(3)

12x - 2y = 6 -------------(4)

Subtracting equation (3) and (4) =>

=> 12x - 9y - (12x - 2y ) = 24 - 6

=> 12x -9y -12x + 2y = 18

=> -7y = 18

=> y = -18/7

So ,

putting y = -18/7 in equ (1)

$\implies \: 4x - 3 \times (\frac{ - 18}{7} ) = 8 \\ \\ \implies4x + \frac{54}{7} = 8 \\ \\ \implies28x + 54 = 56 \\ \\ \implies 28x = 56 - 54 \\ \\ \implies 28x = 2 \\ \\ \implies \: x = \frac{2}{28} \\ \\ \implies x = \frac{1}{14}$

Here ,

Answer

${\purple{\boxed{\large{\bold{x = \frac{1}{14} \: and \: y = \frac{ - 18}{7} }}}}}$