Question

check whether 7+3x is a factor of 3x2+7x

Answer 1

When we factprise 7 + 3x we get 7 + 3 × x
when we factorise 3xcube +7x we get 3 × x × x × x + 7× x when we take x common we get x(3x square + 7).
but 3x square is not equal to 7 + 3x so it is not the factor of 33square + 7