Решить систему уравнений {6x+3=8x-3(2y-4) 2(2y-3y)-4x=2y-8

6x + 3 = 8x - 6y + 12

2x - 6y + 8 = 0

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- 2y - 4x - 2y + 8 = 0

- 4y - 4x + 8 = 0

-x - y - 2 = 0

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2x - 6y + 8 = 0

- x - y - 2 = 0

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x - 7y + 6 = 0

x = 7y - 7

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-2y -4*(7y - 7) - 2y + 8 = 0

- 4y - 28y + 28 + 8 = 0

- 32y = - 36

y = 1.125

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x = 7y - 7 = 7.875 - 7 = 0.875

a6+a8=15

a2*a12=56

a1+5d+a1+7d=15

2a1+12d=15|: 2

a1+6d=7.5

a1=7.5-6d

a2*a12=56

(a1+d)(a1+11d)=56

(7.5-6d+d)(7.5-6d+11d)=56

(7.5-5d)(7.5+5d)=56

7.5^2-(5d)^2=56

56.25-25d^2=56

25d^2=0.25

d^2=0.01

d=0.1

ответ: 0,1