Respuesta :

clarabatzis
Steps
8x−7y=−5
Add 7y to both sides
8x−7y+7y=−5+7y
Simplify
8x=−5+7y
Divide both sides by 8
8x
8 =−
5
8 +
7y
8
Simplify
x=
−5+7y
8

SalmonWorldTopper

Answer:

Therefore, the values of "x" and "y" are -1000/312 and -115/39 respectively.

Step-by-step explanation:

★ Solution :-

[tex] \sf \leadsto 8x - 7y = -5 - - - (i)[/tex]

[tex] \sf \leadsto -x + 4y = -15 - - - (ii)[/tex]

By first equation,

[tex] \sf \leadsto 8x - 7y = -5[/tex]

[tex] \sf \leadsto 8x = -5 + 7y[/tex]

[tex] \sf \leadsto x = \dfrac{-5 + 7y}{8} [/tex]

Now, we can find the original value of y.

[tex] \sf \leadsto -x + 4y = -15[/tex]

[tex] \sf \leadsto \bigg( \dfrac{-5 + 7y}{8} \bigg) + 4y = -15[/tex]

[tex] \sf \leadsto \dfrac{-5 + 7y}{8} + 4y = -15[/tex]

[tex] \sf \leadsto \dfrac{-5 + 7y + 32y}{8} = -15[/tex]

[tex] \sf \leadsto \dfrac{-5 + 39y}{8} = -15[/tex]

[tex] \sf \leadsto -5 + 39y = -15(8)[/tex]

[tex] \sf \leadsto -5 + 39y = -120[/tex]

[tex] \sf \leadsto 39y = -120 + 5[/tex]

[tex] \sf \leadsto 39y = - 115[/tex]

[tex] \sf \leadsto y = \dfrac{ - 115}{39} [/tex]

Now, we can find the original value of x.

[tex] \sf \leadsto 8x - 7y = -5[/tex]

[tex] \sf \leadsto 8x -7 \bigg( \dfrac{ - 115}{39} \bigg) = -5[/tex]

[tex] \sf \leadsto 8x + \dfrac{805}{39} = -5[/tex]

[tex] \sf \leadsto \dfrac{312x + 805}{39} = -5[/tex]

[tex] \sf \leadsto 312x + 805 = -5(39)[/tex]

[tex] \sf \leadsto 312x + 805 = -195[/tex]

[tex] \sf \leadsto 312x = -195 - 805[/tex]

[tex] \sf \leadsto 312x = -1000[/tex]

[tex] \sf \leadsto x = \dfrac{-1000}{312} [/tex]

[tex]\textsf {\underline{Answer-}}\\[/tex]

Therefore, the values of x and y are -1000/312 and -115/39 respectively.

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