Question

check whether 5 x + 1 is a factor of 5 x cube + 26 X square + 35 X + 6 or not

Answer 1

see divide it with the polynomial or put the value of x as '-1÷5

Answer 2

p(x)=5x^3+26x^2+35x+6. 5x=1
p(1/5)=5(1/5)^3+26(1/5)^2+35(1/5)+6 x=1/5
=5(1/125)+26(1/25)+7+6
=1/25+26/25+7/1+6/1
=1+26+175+150/25
=352/25