Question

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

x=-5

B)8x+2=10x-14

8x-10x=-14-2

-2x=-16/:(-2)

x=8

C)1-4•[-5•(x-2)]=21

1-4•(-5x+10)=21

1+20x-40=21/+40

1+20x=61/-1

20x=60/:20

x=30

E)5x+15=10x-10

5x-10x=-10-15

-5x=-25/:(-5)

x=5

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

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

22x=30

30 15

X=— =—

22 11

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

-2x=-35+21+10

-2x=-4/:(-2)

x=2