How do you solve the following system?: $- 4 x - 3 y = 5, x - 2 y = - 15$ $-4x -3y =5, x -2y = -15$

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How do you solve the following system?: $- 4 x - 3 y = 5, x - 2 y = - 15$ $-4x -3y =5, x -2y = -15$

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Answer 1 · 2018-05-17T13:30:54

$x = - 5 and y = 5$ $x = -5 and y = 5$

Explanation:

$- 4 x - 3 y = 5 - - - e q n 1$ $-4x- 3y = 5 - - - eqn1$

$x - 2 y = - 15 - - - e q n 2$ $x - 2y = -15 - - - eqn2$

From the $e q n 1$ $eqn1$ rearrange the equation..

$- 4 x - 3 y = 5$ $-4x - 3y = 5$

Multiplying through by minus $(-)$ $(-)$ ;

$- (- 4 x - 3 y = 5)$ $-(-4x - 3y = 5)$

$4 x + 3 y = - 5 - - - e q n 1$ $4x + 3y = -5 - - - eqn1$

Now solving simultaneously..

$4 x + 3 y = - 5 - - - e q n 1$ $4x + 3y = -5 - - - eqn1$

$x - 2 y = - 15 - - - e q n 2$ $x - 2y = -15 - - - eqn2$

Using Elimination Method..

Multiplying $e q n 1$ $eqn1$ by $1$ $1$ and $e q n 2$ $eqn2$ by $4$ $4$ respectively..

$1 (4 x + 3 y = - 5)$ $1(4x + 3y = -5)$

$4 (x - 2 y = - 15)$ $4(x - 2y = -15)$

$4 x + 3 y = - 5 - - - e q n 3$ $4x + 3y = -5 - - - eqn3$

$4 x - 8 y = - 60 - - - e q n 4$ $4x - 8y = -60 - - - eqn4$

Subtracting $e q n 4$ $eqn4$ from $e q n 3$ $eqn3$

$(4 x - 4 x) + (3 y - (- 8 y) = - 5 - (- 60)$ $(4x - 4x) + (3y - (-8y) = -5 - (-60)$

$0 + 3 y + 8 y = - 5 + 60$ $0 + 3y + 8y = -5 + 60$

$11 y = 55$ $11y = 55$

$y = \frac{55}{11}$ $y = 55/11$

$y = 5$ $y = 5$

Substituting the value of $y$ $y$ into $e q n 2$ $eqn2$

$x - 2 y = - 15 - - - e q n 2$ $x - 2y = -15 - - - eqn2$

$x - 2 (5) = - 15$ $x - 2(5) = -15$

$x - 10 = - 15$ $x - 10 = -15$

$x = - 15 + 10$ $x = -15 + 10$

$x = - 5$ $x = -5$

Therefore;

$x = - 5 and y = 5$ $x = -5 and y = 5$

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How do you solve the following system?: $- 4 x - 3 y = 5, x - 2 y = - 15$ $-4x -3y =5, x -2y = -15$

1 Answer

Explanation:

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Impact of this question

Science

Math

Humanities

... and beyond

How do you solve the following system?: −4x−3y=5,x−2y=−15-4x -3y =5, x -2y = -15

1 Answer

Explanation:

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Impact of this question

How do you solve the following system?: $- 4 x - 3 y = 5, x - 2 y = - 15$ $-4x -3y =5, x -2y = -15$