a,\(x^2+4x+3\)
=\(x^2+3x+x+3\)
=\(x\left(x+3\right)+\left(x+3\right)\)
=(x+3)(x+1)
b,\(2x^2+3x-5\)
=\(2x^2+5x-2x-5\)
=x(2x+5)-(2x+5)
=(2x+5)(x-1)
c,\(16x-5x^2-3\)
=\(-\left(5x^2-16x+3\right)\)
=\(-\left(5x^2-x-15x+3\right)\)
=-[x(5x-1)-3(5x-1)]
=-[(5x-1)(x-3)]
=-(5x-1)(x-3)
\(a.\) \(x^2+4x+3\)
\(=x^2+x+3x+3\)
\(=x\left(x+1\right)+3\left(x+1\right)\)
\(=\left(x+3\right)\left(x+1\right)\)
\(b.\) \(2x^2+3x-5\)
\(=2x^2-2x+5x-5\)
\(=2x\left(x-1\right)+5\left(x-1\right)\)
\(=\left(x-1\right)\left(2x+5\right)\)
\(c.\)\(16x-5x^2-3\)
\(=-5x^2+16x-3\)
\(=-5x^2+15x+x-3\)
\(=-5x\left(x-3\right)+\left(x-3\right)\)
\(=\left(x-3\right)\left(1-5x\right)\)
nhờ mn là giúp mình với ạ , minh đang cần gấp :( 
