How do you solve $8 x - 9 y = 32.5$ $8x-9y=32.5$ and $7 y - 2 x = - 10.5$ $7y-2x=-10.5$ using substitution?

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Answer 1 · 2017-09-09T10:35:49

Solution: $x = 3.5, y = - 0.5$ $x= 3.5 ,y = -0.5$

$8 x - 9 y = 32.5$ $8x-9y= 32.5$ (1) , $7 y - 2 x = - 10.5$ $7y-2x= -10.5$ (2) , From equation (2)

we get $2 x = 7 y + 10.5 or x = 3.5 y + 5.25$ $2x= 7y+10.5 or x= 3.5y + 5.25$ (3), Putting

$x = 3.5 y + 5.25$ $x= 3.5y + 5.25$ in equation (1) we get,

$8 (3.5 y + 5.25) - 9 y = 32.5 or 28 y + 42 - 9 y = 32.5$ $8( 3.5y + 5.25) -9y = 32.5 or 28y+42-9y=32.5$ or

$19 y = 32.5 - 42 or 19 y = - 9.5 or y = - 0.5$ $19y = 32.5-42 or 19 y= -9.5 or y = -0.5$ Putting

$y = - 0.5$ $y = -0.5$ in equation (3) we get, $x = 3.5 \cdot (- 0.5) + 5.25$ $x= 3.5 *(-0.5)+5.25$ or

$x=3.5 :.$ Solution: $x= 3.5 ,y = -0.5$ [Ans]

How do you solve 8x-9y=32.58x−9y=32.58x-9y=32.5 and 7y-2x=-10.57y−2x=−10.57y-2x=-10.5 using substitution?