Question

4x-3y=0
7x-4y=36


please help ​

Answer 1

Step-by-step explanation:

$4x - 3y = 0 - - - - - (i)$

$7x - 4y = 36 - - - - - (ii)$

$multiplying \: eq \: (i) \: by 7 \: and \: eq \: (ii) \: by \: 4 \:$

$28x - 21y = 0 - - - - - (iii)$

$28x - 16y =144 - - - - - (iv)$

$subtracting \: (iii) \: from \: (iv)$

$28x - 16y = 144 \\ 28x - 21y = \: 0 \\ (-) \: \: \: \: \: \: \: \: \: ( + \: ) \: \: \: \: \: \: \: ( - ) \\ - - - - - - - - - - \\ \: \: \: \: \: \: \: 5y = 144$

$y = \frac{144}{5}$

$putting \: the \: value \: of \: y \: in \: eq \: (iii)$

$28x - 21 (\frac{144}{5} ) = 0$

$\frac{140x - 3024}{5} = 0$

$140x = 3024$

$140x - 3024 = 0$

$140x = 3024$

$x = \frac{3024}{140}$

$x = \frac{1512}{70}$

$x = \frac{756}{35}$

$x = \frac{108}{5}$