Question

2,4 si 5 va rog mult.Am nevoie urgent.Dau coroana

Answer 1

2.
a)
2/x=x/8
16=x²
x=4
b)
(x-1)/2=18/(x-1)
(x-1)(x-1)=36(cred ca se vede clar care e raspunsul)
x=7
c)
2/(x-√3)=(x-√3)/24
(x-√3)(x-√3)=48
x²-2√3x+3=0
Δ=b²-4*a*c
Δ=12-4*-45
Δ=192
x1=2√3+8√3/2
x1=5√3
d)36=|x|*|x|
   x=6 si x=-6
4. (2x+3)²-4(x+1)²-1/4
    4x^2+12x+9-4(x^2+2x+1)-1  /4
    4x^2+12x+9-4x^2-8x-4-1
     4x+4/4 ∈N*,deoarece  4x este modelul multiplilor lui 4;
      4x+4
x=1
4x+4 ==>8
x=2 ===>12
x=3 ===> 16
x=4===>20
b)(x+5)²-(x+1)²/8
   8x+24/8
   24∈M8
  8x∈M8
===> 8x+24/8 ∈N*
5)a)
   (x+3)² -2(x-1)=(x+4)(x-4)-5
    x²+6x+9-2x+2=x²-16-5
    6x+9-2x+2=-21
    4x=-32
      x=-8
  b)(x-5)(x+5)-(x-3)²=x-9
     x²-25-x²+6x-9=x-9
      -34+6x=x-9
           5x=25
              x=5
    c)√(x+1)²=3
           |x+1|=3      sau    |x+1|=3
           x+1=3                  -x-1=3
           x=2                       x=-4
      d)(x-√2)²=8
         |x-√2|=2√2    sau    |x-√2|=2√2
            x-√2=2√2             -x+√2=2√2
            x=3√2                   x=-√2