Question

Hei, am nevoie urgent de ajutor,la matematica. Am lipsit tema si nu stiu.
Deci iata exercitiul:

Desfaceti parantezele si reduceti termenii asemenea:
a) -4x(3,3-8a)+4,8a+5,2=
b) -(-$x^{2}$-$x^{3}$)=2x($x^{2}$+$x^{3}$)-3$x^{3}$=
c) -a x (3-b)+2ab=
d) 2a(1-a)+$a^{2}$-2a=

Va rog cit mai repede.Multumesc :)

Answer 1

b)
x³+x²=2x(x³+x²)-3x³
x³+x²=2x⁴-x³
-2x⁴+2x³+x²=0
-x²(2x²-2x-1)=0
x²(2x²-2x-1)=0
x²=0  2x²-2x-1=0

x=0    x²-x-1/2=0

x²-x=1/2

x²-x+1/4=3/4=>x-1/2=√3/2 =>x=1/2+√3/2 
x-1/2=-√3/2=>x=1/2-√3/2

c)ab(x+2)-3ax
x=-(2b)/(b-3)
 asa exercitii merita mai multe puncte
d) 2a(1-a)+a²-2a

2a-2a²+a²-2a
(2a-2a)+(a²-2a²)
-a²+(2a-2a)=>-a²
-a²=0
a²=0
a=0