How do solve the following linear system?: $x + 2 y = 1, - 2 x - 8 y = 4$ $x+2y=1 , -2x -8y = 4$ ?

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How do solve the following linear system?: $x + 2 y = 1, - 2 x - 8 y = 4$ $x+2y=1 , -2x -8y = 4$ ?

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Answer 1 · 2017-02-01T09:33:43

$x = 4$ $x=4$ and $y = - \frac{3}{2}$ $y=-3/2$ or $- 1 \frac{1}{2}$ $-1 1/2$

Explanation:

$x + 2 y = 1$ $x+2y=1$
$- 2 x - 8 y = 4$ $-2x-8y=4$

Reduce the second equation by dividing all terms by $2$ $2$ .

$- 2 x - 8 y = 4$ $-2x-8y=4$

$- x - 4 y = 2$ $-x-4y=2$

Multiply all terms by $- 1$ $-1$ .

$x + 4 y = - 2$ $x+4y=-2$

Separate $4 y$ $4y$ into two.

$x + 2 y + 2 y = - 2$ $x+2y+2y=-2$

In this equation, substitute $(x + 2 y)$ $(x+2y)$ with $1$ $color(red)(1)$ , the value from the first equation.

$x + 2 y + 2 y = - 2$ $x+2y+2y=-2$

$1 + 2 y = - 2$ $color(red)(1)+2y=-2$

Subtract $1$ $1$ from both sides.

$2 y = - 3$ $2y=-3$

Divide both sides by $2$ $2$ .

$y = - \frac{3}{2} = - 1 \frac{1}{2}$ $y=-3/2=-1 1/2$

In the first equation, substitute $y$ $y$ with $- \frac{3}{2}$ $color(blue)(-3/2)$ .

$x + 2 y = 1$ $x+2y=1$

$x + 2 (- \frac{3}{2}) = 1$ $x+2color(blue)((-3/2))=1$

Open the brackets and simplify.

$x - 3 = 1$ $x-3=1$

Add $3$ $3$ to both sides.

$x = 4$ $x=4$

Answer 2 · 2017-02-01T10:14:18

$y = - 1 \frac{1}{2}, x = 4$ $y=-1 1/2, x=4$

Explanation:

$x + 2 y = 1$ $x+2y=1$ -----------(1)

$- 2 x - 8 y = 4$ $-2x-8y=4$ ---------(2)

$2 x + 4 y = 2$ $2x+4y=2$ $(1) \times 2$ $(1) xx 2$ ---------(3)

$- 4 y = 6$ $-4y=6$ --------(2)+(3)

$4 y = - 6$ $4y=-6$

$y = - \frac{6}{4}$ $y=-6/4$

$y = - 1 \frac{1}{2}$ $y=-1 1/2$

Substitute $y = - \frac{6}{4}$ $y=-6/4$ in ----------1

$x + 2 (- \frac{6}{4}) = 1$ $x+2(-6/4)=1$

$x - \frac{12}{4} = 1$ $x-12/4=1$

$x - 3 = 1$ $x-3=1$

$x = 1 + 3$ $x=1+3$

$x = 4$ $x=4$
Substitute #y= -6/4,x=4 in------1

$4 + 2 (- \frac{6}{4}) = 1$ $4+2(-6/4)=1$

$4 - \frac{12}{4} = 1$ $4-12/4=1$

multiply both sides by 4
$16 - 12 = 4$ $16-12=4$

$4 = 4$ $4=4$

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How do solve the following linear system?: $x + 2 y = 1, - 2 x - 8 y = 4$ $x+2y=1 , -2x -8y = 4$ ?

2 Answers

Explanation:

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Science

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Humanities

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How do solve the following linear system?: x+2y=1,−2x−8y=4 x+2y=1 , -2x -8y = 4 ?

2 Answers

Explanation:

Explanation:

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How do solve the following linear system?: $x + 2 y = 1, - 2 x - 8 y = 4$ $x+2y=1 , -2x -8y = 4$ ?