Question 276578
I assume the directions are to multiply out since there is no equal sign.  We would use the FOIL (first, outside, inside, last) method to multiply this out.

{{{(3x+4)(x-5)=(3x)(x)+(3x)(-5)+(4)(x)+(4)(-5)=3x^2-15x+4x-20=3x^2-11x-20}}}