How do you solve the following system?: $4 x + 9 y = - 4, - 21 x + 2 y = 4$ $4x +9y =-4 , -21x +2y = 4$

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How do you solve the following system?: $4 x + 9 y = - 4, - 21 x + 2 y = 4$ $4x +9y =-4 , -21x +2y = 4$

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Answer 1 · 2018-05-30T13:00:46

$x = - \frac{44}{197}$ $x=-44/197$
$y = - \frac{68}{197}$ $y=-68/197$

Explanation:

$4 x + 9 y = - 4$ $4x+9y=-4$ --- (1)
$- 21 x + 2 y = 4$ $-21x+2y=4$ --- (2)

From (1),
$4 x + 9 y = - 4$ $4x+9y=-4$
$4 x = - 4 - 9 y$ $4x=-4-9y$
$x = \frac{1}{4} (- 4 - 9 y)$ $x=1/4(-4-9y)$ --- (3)

Sub (3) into (2)

$- 21 (\frac{1}{4} (- 4 - 9 y)) + 2 y = 4$ $-21(1/4(-4-9y))+2y=4$
$- \frac{21}{4} (- 4 - 9 y) + 2 y = 4$ $-21/4(-4-9y)+2y=4$
$21 + \frac{189}{4} y + 2 y = 4$ $21+189/4y+2y=4$
$\frac{197}{4} y = - 17$ $197/4y=-17$
$y = - 17 \times \frac{4}{197}$ $y=-17times4/197$
$y = - \frac{68}{197}$ $y=-68/197$ --- (4)

Sub (4) into (3)
$x = \frac{1}{4} (- 4 - (9 \times - \frac{68}{197}))$ $x=1/4(-4-(9times-68/197))$
$x = - \frac{44}{197}$ $x=-44/197$

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How do you solve the following system?: $4 x + 9 y = - 4, - 21 x + 2 y = 4$ $4x +9y =-4 , -21x +2y = 4$

1 Answer

Explanation:

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How do you solve the following system?: 4x +9y =-4 , -21x +2y = 44x+9y=−4,−21x+2y=4 4x +9y =-4 , -21x +2y = 4

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Explanation:

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How do you solve the following system?: $4 x + 9 y = - 4, - 21 x + 2 y = 4$ $4x +9y =-4 , -21x +2y = 4$