Question

7 Rezolvaţi în Q ecuațiile:
a 2(x+1)+3(x-2)-4(6-5x) - 3;
* 12(x-3)+5(3-4x)=-7(x+2);
b 4x-9+2(2-3x)-5-3(x-4);
d 2[3(x-5)+ x) = 4(x-3)-3(x+1) - 3.

Answer 1

Explicație pas cu pas:

a 2(x+1)+3(x-2)-4(6-5x) - 3

$2(x+1)+3(x-2) = 4(6-5x) - 3 \\ 2x + 2 + 3x - 6 = 24 - 20x - 3 \\ 5x - 4 = - 20x + 21 \\ 5x + 20x = 21 + 4 \\ 25x = 25 \implies x = 1$

b 4x-9+2(2-3x)-5-3(x-4)

$4x-9+2(2-3x) = 5-3(x-4) \\ 4x - 9 + 4 - 6x = 5 - 3x + 12 \\ - 2x - 5 = - 3x + 17 \\ - 2x + 3x = 17 + 5 \implies x = 22$

c 12(x-3)+5(3-4x)=-7(x+2)

$12(x-3)+5(3-4x)=-7(x+2) \\ 12x - 36 + 15 - 20x = - 7x - 14 \\ - 8x - 21 = - 7x - 14 \\ - 8x + 7x = - 14 + 21 \\ - x = 7 \implies x = - 7$

d 2[3(x-5)+ x) = 4(x-3)-3(x+1) - 3

$2[3(x-5)+ x] = 4(x-3)-3(x+1) - 3 \\ 2(3x - 15 + x) = 4x - 12 - 3x - 3 - 3 \\ 8x - 30 = x - 18 \\ 8x - x = - 18 + 30 \\ 7x = 12 \implies x = \frac{12}{7}$