How do you solve $2 x + 9 y = 10$ $2x+9y=10$ and $x = 4 - 4 y$ $x=4-4y$ ?

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Answer 1 · 2016-05-21T11:53:41

The solution for the system of equations is:
$x = - 4$ $color(green)(x = -4$

$y = 2$ $color(green)(y=2$

$2 x + 9 y = 10$ $2x + 9y =10$ .......equation $(1)$ $(1)$

$x = 4 - 4 y$ $color(blue)(x = 4-4y$ ..............equation $(2)$ $(2)$

Solving by substitution:

Substituting equation $2$ $2$ into equation $1 :$ $1:$

$2 x + 9 y = 10$ $2x + 9y =10$

$2 \cdot (4 - 4 y) + 9 y = 10$ $2 * (color(blue)( 4 - 4y)) + 9y =10$

$8 - 8 y + 9 y = 10$ $color(blue)(8 - 8 y) + 9y =10$

$8 + y = 10$ $8 + y =10$

$y = 10 - 8$ $y =10 - 8$

$y = 2$ $color(green)(y=2$

Finding $x$ $x$ from equation $2 :$ $2:$

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

$x = 4 - (4 \cdot 2)$ $x = 4-(4*2)$

$x = 4 - 8$ $x = 4-8$

$x = - 4$ $color(green)(x = -4$

How do you solve 2x+9y=102x+9y=10 and x=4−4yx=4-4y?