Question

Pls answer the 3 rd and 4 rth

Answer 1

Answer:

3. 3x -5y -4=0..........eqn 1

9x = 2y + 7

9x - 2y- 7= 0..........eqn 2

multiply eqn 1 with 3 table to get 9x

eqn 1-. 9x - 15y - 12 = 0

eqn 2-. 9x - 2y - 7 =0. ( cancelling 9x)

(-). (+). (+) ( changing the symbols )

17y. = -5

$y = \frac{ - 5}{17}$

substitute y value in eqn1

$3x - 5 \frac{ - 5}{17} - 4 = 0$

$3x + \frac{25}{17} - 4 = 0$

Taking 17 as common denominator we get,

$\frac{51x + 25 - 68}{17} = 0$

$\frac{51x - 43}{17} = 0$

$51x - 43 = 0$

$51x = 43$

$x = \frac{43}{51}$

$x = 0.843$

4.

$\frac{x}{2} + \frac{2y}{3} = - 1$

$\frac{3x + 4y}{6} = - 1$

$3x + 4y = - 6$

$3x + 4y + 6 = 0..........eqn1$

$x - \frac{y}{3} = 3$

$x - \frac{y}{3} - 3 = 0$

$\frac{3x - y - 9}{3} = 0$

$3x - y - 9 = 0............eqn2$

Multiply eqn2 with 4

eqn1-. 3x + 4y + 6 = 0

eqn 2 -. 12x - 4y - 36 = 0 ( cancelling -4y and+4y )

15x. -30. = 0

$x = \frac{ - 30}{15}$

$x = - 2$

sub x value in eqn 2

$3( - 2) - y - 9 = 0$

$- 6 - y - 9 = 0$

$- 15 - y = 0$

$- y = 15$

Transferring - into right side

$y = - 15$