Factoring a quadratic polynomial in two variables
I know if I multiply 5x4 I get 20, and that 3x4 + 5 is 17.
(x + 4y)(_x + 5y)
Fill the blank with the only number that works.
Note the _x^2 must equal 3x^2, and (as BobPurley has stated) 5 + 4*3 = 17