Question

11. Rezolvaţi în Z ecuațiile:
a) 9(x - 2) = -63;
c)2(4x + 1) = 2(5x – 7);
e) 1-4. [-5. (x - 2)] = 21;
g) (x+3)(x - 7) = 0;
b) 5(x + 3) = 2(5x - 5);
d) 2(-x + 5) = -8(3x + 2) + 56;
f) 5(x - 2) - 7(x + 3) + 35 = 0;
h) (2x + 6)(x + 3) = 0.
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Answer 1

a) 9x -18 =-63

9x = -45

x = - 5

c) 8x +2= 10x-14

16 =2x

x =8

e) 1-4•[-5•(x-2)]= 21

-4•[-5•(x-2)]= 20

-5•(x-2)=-5

-5x +10 =-5

-5x = -15

x= 3

g)(x+3)(x-7)=0

x^2 -7x +3x -21=0

x^2-4x=21

b) 5x+15 =10x -10

25 =5x

x =5

d)-2x+10=-24x-16+56

22x = 30

x= 30 /22

x= 15/11

f)5x-10-7x-21+35=0

-2x+4=0

-2x= -4

x=2

h)(2x+6)(x+3)=0

2x^2+6x+6x+18=0

2x^2+12x+18=0