Question

5x-7y=-9, 2x+5y=12
Solve it through Substitution method

comes under Simultaneous Linear Equations​

Answer 1

Step-by-step explanation:

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Answer 2

$\huge{\bold{\underline{\underline{Question:-}}}}$

Solve it through Substitution method :-

5x-7y=-9, 2x+5y=12

$\huge{\bold{\underline{\underline{Solution:-}}}}$

In first equation :-

$= > 5x - 7y = ( - 9)$

$= > 5x = 7y - 9$

$= >\large{\purple{\underline{\red{\boxed{\orange{ x = \frac{7y-9}{5}}}}}}}$

Now,

Substituting the value of 'x' in second equation :-

$= > 2x + 5y = 12$

$= > 2( \frac{7y - 9}{5}) + 5y = 12$

$= > \frac{14y - 18}{5} + 5y = 12$

$= > 14x - 18 + 5y = 12 \times 5$

$= > 14y + 5y = 60 - 18$

$= > 19y = 42$

$= >\large{\purple{\underline{\red{\boxed{\orange{ y = \frac{42}{19}}}}}}}$

Now,

Substituting the value of 'y' in first equation :-

$= > 5x - 7y = (- 9)$

$= > 5x - 7( \frac{42}{19}) = ( - 9)$

$= > 5x - \frac{294}{19} = ( - 9)$

$= > 5x = \frac{294}{19} - 9$

$= > 5x = \frac{294 - 171}{19}$

$= > 5x = \frac{123}{19}$

$= > x = \frac{123}{19 \times 5}$

$= >\large{\purple{\underline{\red{\boxed{\orange{ x = \frac{123}{95}}}}}}}$

So, the values of 'x' and 'y' are $\frac{42}{19}$ and $\frac{123}{95}$ respectively.