Răspuns:
a) 2x+5=11
2x=11-5
2x=6
Atunci x=6÷2
x=3
b) 28-5x=-2
-5x=-2-28
-5x=-30 / (-1)
5x=30
x=30÷5
x=6
c) 2x(2x+1)=4
2 ( 2 + 1 ) = 4 4 2 + 2 = 4
d) 3x(X+2)-12=9
3X+6-12=9
3X+6=9
3X=9-6
3X=3
X=3÷3
X=1
e) -12X+2x(x-4)=3x(X+2)-8x
-12X+2X-8=3X+6-8X
-10X-8=3X-8X+6
-10X-8=-5X+6
-10X+5X=6+14
-5X=20 / (-1)
5X=-20
X=20÷5
X=-4
f) 3x(X+5)+16=X+31
3X+15+16=X+31
3X-X=31-31
2X=0
X=0
Sper ca te-am ajutat! Chiar au fost grele! Am pus si in intrebarea din urma.