Răspuns :
a) x²+x-x-1-x²=x-1⇒-1=x-1⇒x=0 b)y²+2y+y+2+3=y²+4y⇒y²+3y+5=y²+4y⇒y=5 d)z²-z-z²+2z=3z-4⇒z=3z-4⇒2z=4⇒z=2 e)(x+1)(x+1)=(x+2)(x+2)-5⇒x²+x+x+1=x²+2x+2x+4-5⇒x²+2x+1=x²+4x+4-5⇒x²-x²+2x-4x=-1+4-5⇒-2x=-2⇒x=1 f)(2u+3)(2u+3)-(2u-1)(2u+1)=12u+8⇒(4u²+6u+6u+9)-(4u²+2u-2u-1)=12u+8⇒4u²+
12u+9-4u²-1=12u+8⇒8=8 Sper ca te-am ajutat!
12u+9-4u²-1=12u+8⇒8=8 Sper ca te-am ajutat!