Question

Ofer 80 de puncte pentru rezolvarea acestui exercitiu!

Answer 1

a)3(x+5)-5(1-x)(1+x)=(x-3)^2+(2x-1)^2+13
3x+15-5(1 - x^2)=x^2-6x+9+4x^2-4x+1+13
3x+15-5+5x^2=x^2+4x^2-6x-4x+9+1+13
 5x^2+3x+10=5x^2-10x+23
 5x^2-5x^2+3x+10x=23-10
 13x=13
 x=13/13
x=1

b)(x-3)(2-x)-(x-5)(5+x)= -2x(x-6)-5(x-1)
2x-x^2-6+3x-(x^2-5^2)= -2x^2+12x-5x+5
 5x-x^2-x^2-6+25=-2x^2+7x+5
 -2x^2+5x+19=-2x^2+7x+5
 -2x^2+2x^2+5x-7x=5-19
     -2x=-14
       x=-14/-2
       x=7
 c)3(1-x)^2-4(x-2)^2+5(x-3)^2=(2x-3)^2+4-x
   3(1-2x+x^2)-4(x^2-4x+4)+5(x^2-6x+9)= 4x^2-12x+9+4-x
   3-6x+3x^2-4x^2+16x-16+5x^2-30x+45=4x^2-13x+13
  3x^2-4x^2+5x^2-4x^2-6x+16x-30x+13x=13-3+16-45
-7x= -19
x= 19/7
x(1-x)+(2-x)^2+(3+X)^2-1=(x-1)(4-x)+(2x+1)(2+x)
x-x^2+4-4x+x^2+9+6x+x^2=4x-x^2-4+x+4x+2x^2+2+x
-x^2+x^2+x^2-x^2+x-4x+6x-4x-x-4x-x=-4+2-4-9
  -7x=-15
 x=15/7