Question

2. Rezolvați ecuațiile de mai jos și identificați valoarea lui x:
1) 45 + 7x = 85 + 5x;
a) x= 45; b) x= 20; x= 85;

2) 30 – x= – 4x + 63;
a) x= 30; b) x= 33; x= 11;

3) 9x – 15 = 7x + 35;
a) x= 35; b) x= 25; x= 15;

4) 7x – 4x + 125 = 225 + x;
a) x= 125; b) x= 225; x= 50;

5) – 3x + 47 = 9x – 13;
a) x= 12; b) x= 5; x= 60;

6) – 8x + 17x – 36 = 5x – 12;
a) x= 36; b) x= 6; x= 12;

Answer 1

Răspuns:

1)

45 + 7x = 85 + 5x;

7x-5x=85-45

2x= 40

x=40/2=20

b) x= 20

2)

30 – x= – 4x + 63;

-x + 4x=63-30

3x=33

x=33/3=11

c) x= 11;

3) 9x – 15 = 7x + 35;

9x-7x =35+15

2x=50

x=50/2=25

b) x= 25

4)

7x – 4x + 125 = 225 + x;

3x-x=225-125

2x=100

x=100/2=50

c) x= 50;

5)

– 3x + 47 = 9x – 13;

-3x -9x=-47-13

-12x= -60

x= 5

b) x=5

6)

– 8x + 17x – 36 = 5x – 12;

-8x +17x - 5x=36-12

4x=24

x=6

b) x=6