Question

What number is to be added to the polynomial x^{2 -5x+4 _{so that 5is zero of the polynomial?}}

Answer 1

Let be x=5
then put the value of x in polynomial
5^2 -5(5) +4
25-25+4=4
x+4=0,x=-4
the -4 should be added to the polynomial to equal the zero
here is prove
5^2 -5(5) +4-4=0
25-25+4-4=0
0=0
hence proved