^{The expression 6x^2 + 17x + 5 can be written in the form (Ax+1)(Bx+5) where A and B are integers. What is the value of AB?}

when we expand (Ax+1)(Bx+5), we get -

ABx^2 + 5Ax + Bx + 5

we know that the coefficient of x^2 in the initial expression is 6, so therefore we know AB must be 6.

hope this helped! please correct me if i am wrong :)