Question

faceti ce stiti va rog e urgent dau coroana​

Answer 1

Răspuns:

Explicație pas cu pas:

1. a+b=(x-2y)+(2x+y+1)=3x-y+1

a-b=(x-2y)-(2x+y+1)=-x-3y-1

2a-b+1=2(x-2y)-(2x+y+1)+1=-5y

2. a)3x+3y+3z=3(x+y+z)

b)2x(x+1)-5(x+1)=(x+1)(2x-5)

c)ax+bx+ay+by=a(x+y)+b(x+y)=(x+y)(a+b)

d)x^2+4x+4=(x+2)^2

e)4x^2-9=(x+3)(x-3)

3. a)x^2+5x+6=0

a=1; b=5; c=6;

delta=b^2-4×a×b=25-24=1

x_1=(-b+radicaldindelta)÷2a=(-5+1)÷2=-4÷2=-2

x_2=(-b-radicaldindelta)÷2a=(-5-1)÷2=-6÷2=-3

b)2x^2-8=0

delta=0^2-4×2×(-8)=+64

x_1=rad64÷2×2=2

x_2=-rad64÷2×2=-2

c)5x^2-2=0

delta=0^2-4×5×(-2)=+40

x_1=2rad10/5

x_2=-2rad10/5