Question

cine imi poate rezolva aceste exercitii : f(x)= xla a doua -5x si f(x)=-x la a doua +4x+5

Answer 1

[tex]1) f(x)= x^{2} -5x \\ x^{2} -5x=0 \\ x(x-5)=0 \\ x_{1} =0 \\ x_{2} =5 \\ \\ 2)f(x)=- x^{2} +4x+5 \\ - x^{2} +4x+5=0 \\ - x^{2} +4x+4+1=0 \\ 1-x^{2} +4(x+1)=0 \\ (1-x)(1+x)+4(1+x)=0 \\ (1+x)(5-x)=0 \\ x_{1} =-1 \\ x_{2} =5[/tex]