Question

Substitute this simultaneous linear equation


`3x {}^( - 1) - {4y}^( - 1) = 5 \\ {2x}^( - 1) + {3y}^( - 1) = 7`
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Answer 1

`{3x}^( - 1) - {4y}^( - 1) = 5 \: ....(1) \\ \\ {2x}^( - 1) + {3y}^( - 1) = 7 \: ....(2)`

__o__o__

`(1)/(3x) - (1)/(4y) = 5 \: ....(1) \\ \\ \\ (1)/(2x) + (1)/(3y) = 7 \: ....(2)`

From equation (1) ;

`(1)/(3x) - (1)/(4y) = 5 \\ \\ (1)/(4y) = (1)/(3x) - 5 \\ \\ (1)/(4y) = (1 - 15x)/(3x) \\ \\ \\ 4y(1 - 15x) = 3x \\ \\ 4y = (3x)/(1 - 15x) \\ \\ y = (3x)/(4(1 - 15x)) \\ \\ \\ y = (3x)/(4 - 60x)`

`(1)/(2x) + (1)/(3y) = 7 \\ \\ \\ (1)/(2x) + ( (1)/(3( (3x)/(4 - 60x) )) ) = 7 \\ \\ \\ (1)/(2x) + ( (1)/( (9x)/(4 - 60x) ) ) = 7 \\ \\ \\ (1)/(2x) + (4 - 60x)/(9x) = 7 \\ \\ \\ (9)/(18x) + (2(4 - 60x))/(18x) = 7 \\ \\ \\ (9)/(18x) + (8 - 120x)/(18x) = 7 \\ \\ \\ (9 + 8 - 120x)/(18x) = 7 \\ \\ (17 - 120x)/(18x) = 7 \\ \\ 18x * 7 = 17 - 120x \\ \\ 126x = 17 - 120x \\ \\ 126x + 120x = 17 \\ \\ 246x = 17 \\ \\ x = (17)/(246)`

`y = (3x)/(4 - 60x) \\ \\ y = (3( (17)/(246)) )/(4 - 60( (17)/(246) )) \\ \\ y = - (17)/(12)`