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8х + 5у = -7
— 7х + бу = — 4

User Scottymeuk
by
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1 Answer

11 votes

Answer: x = -0.2651 and y = -0.9759

Explanation:

Solution by substitution method

8x+5y= -7

-7x+6y= -4 = 7x-6y=4

Suppose,

8x+5y=-7→(1)

7x-6y=4→(2)

Taking equation (1), we have

8x+5y= -7

⇒8x= -5y -7

⇒x= -5y-7 / 8 →(3)

Putting x= -5y-7 / 8

in equation (2), we get 7x-6y=4

7(-5y-7/8)-6y=4

⇒-35y-49-48y=32

⇒-83y-49=32

⇒-83y=32+49

⇒-83y=81

⇒y= 81 / -83

⇒y= -0.9759→(4)

Now, Putting y= -0.9759 in equation (3), we get

x= -5y-7

x= -5(-0.9759)-7/8

⇒x= 4.8795-7/8

⇒x= -2.1205/8

⇒x= -0.2651

∴x= -0.2651 and y = -0.9759

User Sanoob
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6.0k points