Question

va rog mult de totb doamna Renatemambouko sa ma ajutati ,pentru ceilalti   daca nu stiti nu raspundeti va rog lasati pe altcineva  , mie imi trebuie numai 2.3.4 de la toate imaginile va multumesc 

Answer 1

a)
a=2k    k=a/2=
b=5k    
a/2=b/5
5a=2b
a=2b/5=0,4b=40%b
p=40%

b)
a=2k
b=5k

3a+b=44
3*2k+5k=44
6k+5k=44
11k=44
k=44/11
k=4

a=2*4=8
b=5*4=20


Deci 5a-b= 5*8-20=40-20=20

3.
x³-4x²+ax+b
P(1)=-3

1³-4*1²+a*1+b=-3
1-4+a+b=-3
a+b=0

P(-1)=7
(-1)³-4*(-1)²+a*(-1)+b=7
-1-4-a+b=7
-a+b=12

a+b=0
-a+b=12
2b=12
b=6
a=-6

inlocuim a si b in P(x)= x³-4x²+ax+b=x³-4x²-6x+6
P(x)+9x-6=x³-4x²-6x+6+9x-6=x³-4x²+3x=x(x²-4x+3)=x(x²-x-3x+3)=
=x[x(x-1)-3(x-1)]==x(x-1)(x-3)

pag.2
2
206 ha x 19 to/ha =3914
3914-608=3306
3306:2=1653 to lot 1        1653:19=87 ha
1653+608=2261 to lot 2    2261:19=119 ha

3
3x+y=-2
-5x-y=2
-2x=0
x=0
y=-2

4.
(x+1)²+2(x-7)+1=
=x²+2x+1+2x-14+1=
=x²+4x-12=
=x²+6x-2x-12=
=x(x+6)-2(x+6)=
=(x+6)(x-2)=
=(x-2)(x+6)


pag.3
3.
x(1-√2)≥4-2√8
x(1-√2)≥4-4√2
x≥4(1-√2)/(1-√2)
x≥4

4.
x=nr banci
x+6=2(x-5)+1
x+6=2x-10+1
x=15 banci
x+6=15+6=21 elevi