Question

Aceste 2 exercitii va rog..

Answer 1

Răspuns:

Explicație pas cu pas:

9b)

4(x + y) - 3x + y = -6

5(x - 3y) - 9x = 3 - 16y

4x + 4y - 3x + y = -6

5x - 15y - 9x + 16y = 3

x + 5y = -6

-4x + y = 3

y = 3 + 4x

x + 5(3 + 4x) = -6

x + 15 + 20x = -6

21x = -6 - 15 = -21

x = -21 : 21 = -1

y = 3 + 4*(-1) = 3 - 4 = -1

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10a)

x/2 - y/4 = -2

5x/6 + 3y/4 = 4/3

2x - y = -8

10x + 9y = 16

y = 2x + 8

10x + 9(2x + 8) = 16

10x + 18x + 72 = 16

28x = 16 - 72 = -56

x = -56 : 28 = -2

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