Question

ex 1 si 2 ajutor varog în afara de ambele f- uri

Answer 1

ex. a) 7x=3+4
7x=7
x=7:7
x=1

b) 3x+45=72
3x=72-45
3x=27
x=27:3
x=9

c) 9x+11=7x+3
9x-7x=3-11
2x= - 8
x= - 8:2
x= - 4

d) 7-3x=27-5x
- 3x+5x = 27- 7
-2x=20
x= -20:2
x=-10
e) 5x-14=42-2x
5x+2x=42+14
7x=56
x=56:7
x=8

ex. 2. a)x-3=2x+4
x-2x= 3+ 4
- x=7
x= - 7

Answer 2

1.a)7x-3=4
   7x=3+4
7x=7
x=1
b)3x+45=72
3x=72-45
3x=27
x=27/3=9
c)9x+11=7x+3
9x-7x=3-11
2x=-8
x=-8/2=-4
d)7-3x=27-5x
-3x+5x=27-7
2x=20
x=20/2=10
e)5x-14=42-2x
5x+2x=42+14
7x=56
x=56/7=8
.......................................
2.a)x-3=2x+4
x-2x=4+3
-x=7,,x=-7
b)x-5/6=2.2/3
x=2.2/3+5/6
x=8/3+5/6amplificam cu 2 la 8/3
x=16/6+5/6=21/6simplificam cu3=7/2
c)x/3-4=2x+1/4
x/3-2x=1/4+4 aducem la acelasi numitor ,amp.pe 2x cu3si pe 4 cu 4
x/3-6x/3=1/4+16/4
5x/3=17/4
5x=17.3/4
5x=21/4
x=21/4.1/5=21/20
d)1.1/3-x=2
4/3-x=2
-x=2/2/4
-x=2.3/4
-x=3/2....x=-3/2
e)2x-1/4=1/3x+1/2
2x-1/3x=1/2+1/4 aducem la acelasi numitor..amp cu 3 pe 2x si cu 2pe 1/2
6x/3-1/3=2/4+1/4
5x/3=3/4
5x=9/4
x=9/4/5
x=9/4.1/5=9/20
  (/)-linie de fractie
(.)-inmultire
sper ca ai inteles