Question

$d)5 {x}^{2} - x + 1 = x + 4 {x}^{2}$

Answer 1

$5x^{2}-x+1=x+4x^{2}\\ 5x^{2}-x+1-x-4x^{2}=0\\ x^{2}-2x+1=0\\ (x-1)^{2}=0\\ x-1=0\\ x=1$