Question

Va rog daca ati putea sa ma ajutati ​

Answer 1

2)18+x=18×3

18+x=54

x=36

3) a)Gf n Ox=》 f(x)=0

-2x+1=0

-2x=-1

x=1/2

A(1/2;0)

Gf n Oy=》x=0

f(x)=-2×0+1

f(x)=1

B(0,1)

si reprezinta tu aceste 2 puncte într-un sistem de coordonate XOY

b)verificam daca f(2)=5

-2×2+1=-3 diferit de 5

deci puncul P(2,5) nu apartine Gf.

4.a/b=15/10

a/b=3/2

2a=3b《=》

(3a-2b)/(5a+6b)=

(3×3b/2 -2×2a/3)/(5×3b/2+6×2a/3)=

(9b/2-4a/3)/(15b/2+4a)=

(6a/2-4a/3)/(10a/2+4a)=

(18a/6-8a/6)/9a=

10a/6 × 1/9a=10a/54a=10/54=5/27

5.(a-2)(b+3)=5

1×5=5. sau 5×1=5 sau (-1)×(-5)=5. sau (-5)×(-1)=5

si luam cazurile separat si aflam a si b

I. a-2=1=》a=3

b+3=5=》b=2

Ii. a-2=5=》a=7

b+3=1=》b=-2

Iii. a-2=-1=》a=1

b+3=-5=》 b=-8

IV. a-2=-5=》 a=-3

b+3=-1=》 b=-4

deci perechile sunt (3,2); (7,-2); (1,-8); (-3,-4).