Question

1) 0,2x²+3x-20=
2)10x2+5x-5=​

Answer 1

$1)0,2x^{2} +3x-20=\frac{1}{5}x^{2} +3x-20=\frac{1}{5}*(x^{2} +15x-100)=\frac{1}{5}*(x^{2} +20x-5x-100)=\frac{1}{5}*(x*(x+20)-5(x+20))=\frac{1}{5}*(x+20)*(x-5)=0,2(x+20)*(x-5)\\2)10x^{2} +5x-5=5(2x^{2} +x-1)=5(2x^{2} +2x-x-1)=5(2x*(x+1)-(x+1))=5(x+1)*(2x-1)$